100 (1973). (331) Visweswariah, K., Jayaram, M., Pestic. Sci., 3, 283 (1973). (332) Voss, G., Blass, W., Analyst (London), 98, 811 (1973). (333) Waldron, A. C., Bull. Environ. Confam. Toxic ~ / .9, , 305 (1973). (334) Wallcave, L., Bronczyk, S., Gingell, R., J. Agr. FoodChem.. 22. 904 119741. (335) Wasfy, W.S.,-jordan, L. S.. Jolliffe, V. A,. Coggins. C. W., Jr., ibid., 21, 629 (1973). (336) Webber, T. J. N., Box, D. G., Analyst (London), 98, 181 (1973). (337) Weisgerber. I., Kohli, J.. Ravindernath. K., Klein, W., Korte, F., J. Agr. f o o d Chem., 22, 609 (1974). (338) Westlake, W. E., Ittig, M., Ott, D. E., Gunther, F. A,, ibid., 21, 846 (1973). (339) White, E. R., AI-Adil, K. M., Winterlin, W. L., Kilgore. W. W., Bull. Environ. Confam. Toxi-
cob, 10, 140 (1973). (340) White, E. R., Bose, E. A,, Ogawa. J. M., Manji, B. T., Kilgore. W. W., J. Agr. Food Chem., 21, 616 (1973). (341) White, E. R., Kilgore, W. W., ibid,, 20, 1230 (1972). (342) Whiteoak, R. J., Crofts, M., Harris, R. J., Pestic. Sci.. 3, 319 (1973). (343) Whitten. C. J., Bull, D. L., J. Agr. FoodChem., 22, 234 (1974). (344) Williams, D. T., Blanchfield, B. J.. J. Ass. Offic. Anal. Chem.. 33. 1358 11973). (345) Williams, I. H., B ~ O A M. , J,, J. 'agr. food Chem.. 21. 399 119731. (346) Williams, I."., Brown,'M. J., Finlayson, D. G., ibid., 20, 1219 (1972). (347) Willmott, F. W., Dolphin, R. J., J. Chromatogr. Sci., 12, 695 (1974). (348) Woodham, D. W., Hatchett, J. C.. Bond, C. A., J. Agr. FoodChem., 22, 239 (1974).
(349) Woodham, D. W., Reeves, R. G., Williams, C. B., Richardson, H., Bond, C. A,, ibid., p 731. (350) Woolson, E. A,. J. Ass. Offic. Anal. Chem., 57, 604 (1974). (351) Yip, G.,ibid., 56, 299 (1973). (352) /bid., 57, 299 (1974). (353) Young, S. J. V., Finsterwalder, C., Burke, J. A,, /bid., 58, 957 (1973). (354) Zelenski, S. G., Tashiro, J., Worthen, L. R., Olney, C. E., J. Chromafogr., 84, 67 (1973). (355) Zweig, G., Ed., "Analytical Methods for Pesticides, Plant Growth Regulators, and Food Additives," Vol. VI, "General," Academic Press, New York, London, 1972;' (356) Zweig, G., Sherma, J.. Analytical Methods for Pesticides, Plant Growth Regulators, and Food Additives," Vol. Vll, "Thin Layer and Liquid Chromatography and Analysis of Pesticides of International Importance," Academic Press, New York, London, 1973.
Petroleum J. M. FRASER Union Oil Company of California, Brea, CA 9262 1
This, the twelfth in a series of reviews of analytical chemistry in the petroleum industry ( I A - I I A ) , is sponsored by the Division of Petroleum Chemistry of the American Chemical Society. Its objective is to cover the most important and relevant publications appearing essentially in 1972 and 1973. Specifically, it covers the papers abstracted in Chemical Abstracts, in the American Petroleum Institute Refining Literature Abstracts, and in Analytical Abstracts (London) for the period of July 1972 through June 1974. Thus, this review begins where the previous one left off and the general format which has evolved from the previous issues is being continued. References conform to the Chemical Abstracts "Guide for Abbreviating Periodical Titles." In addition where a reference publication might not be readily available, the abstract journal has been appended to that for the original
source. The abbreviations C.A., A.P.I.A., and B.A.A. are used to identify the abstract journals cited above. These abbreviations are followed by the volume number, the abstract number, and the year. The abstract searching was done by C. A. Simpson, Mobil Research and Development Corp., J. F. Hickerson, Exxon Co., U S A . , and R. W. King, Sun Oil Company. The collected abstracts were then screened and organized by subjects. Each collection of abstracts was then additionally reviewed, screened, and organized by fourteen authors of the eleven subjects or subsections which follow. The generous assistance of the abstractors and of the authors, many of whom have contributed to previous reviews, is very much appreciated and the production of this review is due to their combined efforts.
Crude Oils
oils (90B). Fabre et al. described a rapid gas chromatographic method for the determination of n-Clz-C32 hydrocarbons from rock extracts (34B). Kuklinskii and Pushkina examined the aromatic fractions boiling above 400 "F from Korobkov and Zhirnov crudes (51B). The benzene, naphthalene, and phenanthrene nuclei accounted for 58, 23, and 12%, respectively, of the total aromatic rings. Kajdas et al. separated the aromatic hydrocarbons from various high boiling fractions of Romashkino crude oil and tabulated their physical and chemical properties (45B). Przybylski and Ligezowa fractionated the aromatic compounds from two different crude oils, examined the fractions by UV and IR spectrometry and discussed equations for calculating hydrocarbon fractions from spectrometric data (85B). Egiazarov et al. determined the amounts of all the possible c 6 - C ~aromatics, as well as n-propyl- and isopropylbenzene in the fractions of 5 Ostashkova crudes boiling below 300 "F, and the amounts of 60 individual aromatic compounds in the 300-400 O F fractions (30B). Some correlations of aromatic content with the stratigraphy of the reservoirs were presented. Brodskii et al. fractionated the aromatic compounds boiling between 660-840 O F from Ro-
F. C.Trusell Marathon Oil Go, Littleton, Colo.
Hydrocarbons. Sergienko et al. determined the overall content and the distribution of the C5-C33 n-paraffins in 9 USSR crude oils (97B).The fields were selected as potential commercial sources of n-paraffins. The analytical procedure is fully described. Kurbskii et al. determined that the ratio of the Cll-C14 to C15-C18 n-paraffins from 5 Tartar crudes could be correlated with the degree of conversion of the crude in terms of the average cyclicity of the higher saturate fractions and in terms of an index derived by statistical treatment of data on the physical and chemical properties of the crude (55B). Rudakova and Timoshina determined the content of C9-CS1 n-paraffins in six crude Authors have not been supplied with free reprints for dlstrlbutlon. Extra copies of the review issue may be obtalned from Speclal Issues Sales, ACS, 1155 16th St., N.W., Washington, DC 20036. Remit $4 for domestlc U.S. orders; add $0.50 for addltlonal postage for forelgn destlnallons.
A N A L Y T I C A L CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
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mashkino and Arlan crudes and examined each fraction by mass spectrometry (15B). Successive fractions contained progressively lower concentrations of hydrocarbons and higher concentrations of thiophene compounds. Kuliev et al. fractionated 90 O F cuts from 660-930 O F of Sangachaly Sea crude by liquid chromatography and determined the hydrocarbon group-type composition of each fraction (53B). Barabadze et al. separated the aromatics from four boiling ranges from 510-590 OF and tabulated the physical constants and compositions of each fraction ( 9 B ) . Maksimova et al. have reported the physical and chemical properties of the aromatic fractions of ten Western Siberian crudes (64B). Egiazarov et al. have reported analyses of aromatic hydrocarbons from the fraction boiling above 400 O F from two Belorussian crudes (29B). Melikadze et al. (68B) and Usharauli et al. (106B) described investigations leading to the identification of adamantane and 1-methyl-adamantane in several Georgian SSR crudes. Powell and Mckirdy determined the pristane/phytane ratio of Australian crudes (84B). Values ranged from 1 to 12, and generally increased with increasing Bureau of Mines correlation index values. Petrov et al. determined the total amounts and the distributions of 24 individual c9-c~~ isoprenoids in various Russian petroleums (79B). Yakubson et al. made a detailed study of the 390-480 O F saturates from Krasnodar and Azerbaijan crude. The tricyclic saturates were given particular attention. In addition to adamantane, four basic structures, all containing both fused and bridged rings, were identified (109B). Khramova et al. determined the composition of that portion of Samotlorsk and Novoportovsk crudes boiling below 450 O F . The results were tabulated and the two oils compared (47B). Kuklinskii et al. analyzed three samples of Zhirnovskii crude taken from horizons of increasing depth, and showed the trends in physical and chemical properties (50B). Rudakova et al. separated a mixture of solid hydrocarbons from Dolina crude by treatment with urea-thiourea in methylene chloride-methanol (89B).The adducts were decomposed and the liberated hydrocarbons were fractionated by liquid chromatography. Physical and chemical properties for each fraction were tabulated. Postnov et al. used gas chromatography for a detailed study of the material separated from Mangyshlak crude by urea dewaxing (82B). Kuklinskii and Pushkina separated the 390-880 O F portion of Korobkov and Zhirnovskii crudes into two fractions by adduction with thiourea. The structures in each fraction were deduced from their IR spectra and from n-d-M calculations (52B).Korotkii et al. dewaxed four fractions boiling above 570 'F from each of 5 Caspian east coast crudes, and selectively dehydrogenated the non-adducted material (48B).The IR spectra of the resulting aromatics were used to infer the structure of the parent naphthenes. Varfolomeev et al. employed mass spectrometry to characterize the distillate oils from Tyumen crude and the refined, deparaffinated products from these distillates (107B).The properties of the resulting lubricating oils were correlated with their chemical composition. Mardanov et al. separated the resins from the kerosine-gas oil fractions of Balakhansk and Sangachal'sk crudes and obtained their IR spectra (65B). They found the resins to be more than 50% aromatic, to contain carbonyl groups, and to have most of the heteroatoms in rings rather than in aliphatic bridges. Egiazarov et al. identified 89 aliphatic and 5 aromatic hydrocarbons in the 257-302 O F fraction of Ostashkov petroleums (28B).This fraction contains 35-40% normal and 25-30% isoparaffins, 25-30% naphthenes, and 5-10% aro170R
matics. Khodzhaev et al. determined the amounts of individual hydrocarbons in gasolines from Kara-Ulbazar and Dzharkak petroleums (46B), and compared the compositions of the two products. Bobyleva et al. quantitatively determined 87 individual hydrocarbons of a Buktyl deposit condensate, and reported the concentrations of those regarded as commercially important (14B). Magaril et al. quantitatively determined the aromatic hydrocarbons in condensates and gasoline fractions from various fields in the Tyumenskaya region, and discussed trends in the relative concentrations with depth and the age of the deposits (62B). Shefter et al. determined the C4-Clo saturate compounds in straight-run gasolines from 5 Russian crude Oils (99B). Kuras and Svajgl evaluated the gasoline fraction of Romashkino crude as a reformer feedstock by mass spectrometry (54B),and then showed that identical results could be obtained by using gas chromatography or silica gel chromatography (103B). Heterocompounds. Aivazov et al. made a detailed analysis of the sulfur compounds in Arlan and Shkapovsk crude oils, and were able to account for more than 50% of the total sulfur ( 3 B ) . Elemental sulfur, mercaptans, and H2S were not detected. Nikitina et al. determined the compositions of the sulfides from narrow boiling fractions of the kerosine-gas oil portion of Arlan crude. Mono-, bi-, and tricyclic sulfides were found, depending on the boiling range (73B).Egiazarov et al. measured the distribution of monoand disulfides in the kerosine-gas oil fractions of Belorussian crude oils. Significantly higher amounts of both compound classes were found in crudes from intersalt formations compared to crudes from subsalt formations (27B). Obolentsev et al. determined the types of sulfur compounds and the thermal stability thresholds for crudes and distillates of five deposits in western Siberia (74B). Castex has reviewed the techniques for the separation and analysis of sulfur compounds with emphasis on UV spectrophotometry and spectrofluorimetry (16B). Rall et al. have published a comprehensive summary covering 20 years of work by the Separation and Identification Section of API Project 48 on sulfur compounds in crude oil (86B). Sevast'yanova and Ivchenko determined the distribution of sulfur compounds of Arlan crude in the fraction boiling below 350'. Sulfides were the most abundant class of sulfur compound (98B). Agrawal et al. determined the distribution of sulfur compounds in crudes from the Darius field. Mercaptans predominated in the fractions below 150', sulfides in the 150-250' fraction, and thiarenes in the higher boiling fractions ( 2 B ) . Gusinskaya separated the sulfur and nitrogen compounds boiling below 320' in Uzbekistan petroleum. He identified thiophenes, thioindans, quinolines, thiozoles, and porphyrins (38B). Ben'kovskii et al. determined both total and basic nitrogen, in 12 Bashkir crudes and 9 Siberian crudes and tabulated the data (11B).The basic nitrogen in 8 of the samples was present entirely as tertiary amino groups. The same investigators separated the nitrogen compounds of an Arlan crude naphtha and found them to be 90% alkylanilines and 10%N-alkylaniline (10B). Anbrokh et al. obtained the hydrocarbons from the methyl esters of aliphatic acids in the diesel fuel fraction of Romashkino and Mukhanevo crudes. By GC they identified all of the Clo-C25 n-alkanes, and six terpenic C14-C20 isoalkanes, including pristane and phytane ( 5 B ) . Anbrokh also investigated the naphthenic acids from these fractions and found them to be mainly derivatives of
ANALYTICAL CHEMISTRY, VOL. 4 7 , NO. 5, APRIL 1975
cyclopentane and pentalane ( 4 B ) .Six membered rings were found primarily in tricyclic naphthenic acids. McKay et al. proposed an analytical method for acids in the 695-995 O F and 995-1250 O F boiling ranges (59B), using absorption and gel permeation chromatography for separation and gravimetry and IR spectrometry for the analysis. Results for 8 crudes are shown. Chertkov et al. characterized the oxygen compounds of the 390-575 "F fraction of Neftyanye Kamni crude. The principal components were esters of dibasic acids having molecular weights around 380, and acids and resins of molecular weight 375 (17B). Shale Oil. Decora et al. have found that broad-line NMR can be used to estimate the oil yield from shales, along with the organic carbon content (21B). Thirty samples per hour can be run. The signal strength can be correlated to the Fischer assay oil yield. Cook has developed an equation relating the organic carbon content of the Green River shale to the Fischer assay oil yield (2073). Jensen et al. have characterized two shale oils produced by in-situ combustion and compared their properties with those of oils from aboveground retorts (43B). The oils produced by aboveground retorting were from both mine-run shale and shale which had been crushed and screened. The differences observed between all three groups are discussed. Murphy et al. identified unbranched aliphatic acids, aliphatic dibasic acids, isoprenoid acids, isoacids, and monounsaturated fatty acids from the alkaline hydrolysate of kerogen from Green River shale (70B).Additional information on the structure of Green River kerogen was derived. Poulson et al. employed a subtractive gas chromatographic technique to determine the amount of different compound types of shale oils (83B). Lille et al. have studied the proton NMR, UV, and IR spectra of the phenolic fractions of shale oils, and established the presence of 2,5-dimethoxystyrene (58B). The presence of other phenolic compounds with a conjugated double bond in a side-chain was also suggested. In another study, heavy shale oil was separated into hydrocarbons, neutral oxygen compounds, and phenols (57B).Each fraction was examined by l3C NMR in addition to the above techniques. Structural information about heavy shale oil was deduced. Asphalts and Residues. Jewel1 et al. have proposed a combination of techniques for obtaining compositional data on residuals. The sample was fractionated by extraction and adsorption chromatography, and the fractions were examined by GC and by UV and NMR spectrometry. Results from residuals of four crudes are given (44B). Ratovskaya separated the asphaltenes from Arlan crude into eight fractions with a series of chromatographic columns. Sulfur, in the form of sulfoxides and sulfides, was uniformly distributed through all fractions. The lighter fractions contained most of the porphyrin compounds, while the heavier fractions contained more of the highly condensed aromatic rings (88B). Bikbaeva et al. separated the asphaltenes from this crude into seven fractions by precipitation from benzene with increasing amounts of heptane. Luminescence and IR spectra are presented, along with compositional data (13B). Magaril and Svintitskikh studied the decomposition of asphaltenes from western Siberian crudes at 390 "C. The coke yields and the composition of the volatile products are given (63B). Gawal and Ruthkowski describe the isolation of asphaltenes and resins from Romashkino type crudes, and the subsequent characterization of these two fractions (36B). 172R
Ivchenko and Garipova studied the effect of the sulfur content of a petroleum on the sulfur content of the residue (42B). Equations and graphs describing this relationship are presented. A detailed tabulation of the properties of several medium and high sulfur crudes is also given. Bikbaeva and Markhasin fractionated asphaltenes from Arlansk crude by heating in vacuo (12B). The absorption and luminescence spectra of the fractions were obtained. Eigenson and Ivchenko developed a nomogram for estimating the density and kinematic viscosity of a residuum if the density of the whole crude and the amount distilled off are known (31B). Metals and Salts. Serbanescu determined the distribution of trace metals and porphyins in a series of Romanian crudes (95B).Present were V, Cu, Cd, Ni, Co, and Fe. Visible and IR spectra were presented for the porphyrins, as well as polarographic data. The problem of their origin is also discussed. Etemad-Maghadam and Raisszadeh isolated and characterized the porphyrins from Alwag (Iranian) crude and found them to be predominately of the deoxyphylloerythroetio type (33B).Nearly all of the vanadium is in porphyrin structures, and most is distilled below 1100 OF. The vanadium content of paraffinic oils is generally higher than that of asphaltic oils. Kotova et al. attempted to deduce some relationship between the V, Ni, and N contents of Mangyshlak petroleums, but found none (49B). They postulated the presence of V quinolates and developed an ion exchange technique for their isolation. Hohmann et al..examined 42 crude oils, representing 90% of the oils used in West Germany, for fluoride, but found none ( 4 1 B ) . The method, which involved sample combustion, adsorption in alkaline solution, and potentiometric measurement with a fluoride sensitive electrode, has a lower limit of detection of 0.03 ppm. Wilson et al., using sodium biphenyl to cleve the C-F bond and a LaF3 electrode, examined 10 crude oils from various areas and found the fluoride content to range from 0.14-1.1 ppm (108B). Hinkle reported a new method for determining mercury in crude oils. The sample is oxidized in a Schoniger combustion flash and the Hg is collected on a Ag gauze. The gauze is heated in an induction furnace and the light absorption by the mercury vapor is measured (40B). Zaghloul et al. used neutron activation analysis to determine V, S, Na, and Br in Arab crude oils (110B). Agrawal and Fish compared three methods of ashing for the determination of V, Fe, Ni, Cu, Mg, Na, K, and Ca. Wet ashing gave the most reliable results (1B). Non-Routine Characterization. Satter-Zade et al. measured the optical activity of Zhiloi Island crudes of their dearomatized fraction (92B-94B). They found that optical activity increased with increasing depth of the producing formation, but decreased after dearomatization. Rastorguev et al. determined the thermal conductivity of 29 crude oils from USSR deposits at temperatures of 20200' (87B).The value depended on the physical and chemical properties of the crude, and on its hydrocarbon grouptype composition. Naziev and Nurberdyev measured the thermal conductivities of Turkmen crudes between 16 and 48' (71B).In all cases, this value decreased with increasing temperature. API Project 60 continued to produce useful techniques for examining the heavy ends of petroleum. McKay and Latham combined various chromatographic techniques with fluorescence spectrometry to establish the presence of previously unreported polynuclear aromatic hydrocarbons in Recluse, Wyoming crude oil (61B).A similar study was carried out with Wilmington and Wasson crudes (60B).Details of the research done for this project have been given in
A N A L Y T I C A L CHEMISTRY, VOL. 47, NO. 5 , APRIL 1975
periodic reports (6B-8B). Hinds has discussed the application of the heavy ends analysis in predicting product yields and properties (39B). The matching of spilled oil with potential sources has continued to draw attention. Cole found he could identify crude oils on the basis of gas chromatograms obtained from a 45-meter X 0.25-mm capillary column coated with OV101 and temperature programmed from 50-310 “C (18B). Miller used 80 crude oils from the world’s major fields to develop a method based on the properties and composition of the 600 O F + fraction. These properties include the C and S isotopic composition, and the S, N, V, and Ni content (69B). Downer and Inkley showed the thermal expansion of crude oils was about 8% greater than for distillate products of the same density (26B),and warned against the use of ASTM/IP tables (derived for products) on crude oils. Eigenson and Ivchenko used 842 narrow boiling fractions from 39 sour crudes of the Ural-Volga and western Siberian regions to develop nomograms relating the density of the crude and the boiling point of the fraction to the density of the fraction (32B). Pichler and Herlan separated a Saar coal-tar distillate boiling below 700 OF into acidic, neutral, and basic fractions by extraction and examined each fraction by low voltage, high resolution mass spectrometry (80B). Oehlmann has reviewed the separation of petroleum into its fractions and the characterization of these fractions by both traditional and non-routine analytical methods (77B). Zimina et al. combined GC, MS, NMR, and distillation to derive a relationship between structures and the physical and chemical properties of crude oils. Fourteen types of sulfur were identified, and a relation between hydrocarbon structure and oil deposit depth was established ( I I I B ) . Sergienko et al. analyzed a crude oil from a new Koyun field and reported its physical and chemical properties (96B). Routine Analytical Data. The physical and chemical properties of petroleum and the testing of them have been reviewed by Rumpf (91B).An abbreviated assay for a preliminary evaluation of a crude oil has been proposed by O’Donnell (75B). Characterization of Transylvanian ( 7 8 B ) , Kirgiz SSR (102B),and Olen’e crude oils (101B) have been carried out by conventional methods. The 700-995 OF fractions of a Gach Saran (23B, 24B, 104B), Prudhoe Bay ( 1 9 B ) , and Swan Hills (22B, 25B) crude oils have been characterized by methods developed under API Project 60. Distillation Data. O’Donnell reported a method of constructing a simulated T B P curve from gas chromatographic data on narrow boiling distillation cuts (76B). Distillation curves for any finite cut can be calculated by integration over the desired temperature interval. Trusell and Mikulas reported results of simulated T B P distillations of whole crudes by gas chromatography ( I 0 5 B ) .The result of a separate analysis of the front end through n-octane is used as the internal standard. Miscellaneous. Pierre modified a double-beam spectrophotometer to study the IR reflectance spectra of oil slicks on water, and discussed the problems of observing oil slicks a t sea ( 8 I B ) . Nemirov and Silkina evaluated the errors in using the Karl Fischer method of determining water in crude oils. The basic errors are in the determination of the end point and in determining the titer. A systematic error is caused by sulfur compounds, for which correction should be made (72B).
Mechalas et al. used a mixed culture of micro-organisms to study the microbial degradation of Santa Barbara crude oil. Low molecular weight compounds are degraded more rapidly than those of higher molecular weight, with the nparaffins disappearing in the shortest time (67B). Grodde discussed the anomalous flow properties of waxy crudes (37B). He developed equations to describe their flow in different transport configurations and discussed the difficulties in the measuring techniques. Kuz’menkova e t al. determined the concentrations of petroleum in porous media by igniting the sample in oxygen and measuring the produced H20 and COz (56B),and discussed the behavior of the sample during combustion. Ferris and Jepson determined the organocarbon in clays by burning the sample in oxygen, purifying the evolved COP, absorbing it in ethanolamine and DMF, and titrating (35B).Smith and Martin described a scheme for determining the hydrocarbon composition (in terms of asphaltenes, aromatics, and paraffins) of source rocks (IOOB). The hydrocarbons are obtained by solvent extraction, and separated by silica gel TLC. Mark et al. used IR spectrometry to estimate the crude oil content of sediments which also contained biological matter (66B).Both types of material absorb a t 2925 cm-l (-CHZ-stretch) but biological matter also absorbs a t 1650 cm-I (-the protein-”-band), whereas crude oils do not. By measuring a t both frequencies, the contribution from each type of material can be deduced.
Fuels, Gaseous and Liquid J. D. Beardsley The Standard Oil Co. (Ohio), Cleveland, OH
Natural, Refinery, a n d Manufactured Gases. Schuster (107C) gives the carbon-hydrogen-oxygen-nitrogen ratios of 36 models for natural, refinery, and manufactured gases, as well as their actual and elemental volume compositions. These data can be used for density and combustion calculations. He (106C) tabulates ignition limits, fuel ratios, and heating values for hydrogen, carbon monoxide, C1-C4 paraffins, C2-C4 olefins, and natural gas, LPG, refinery gases, and manufactured gases in the form of a work sheet. The correlation of these parameters is discussed. He also (108C) gives the heating values and Wobbe indexes of C 1-C4 alkane- and alkene-air mixtures containing 0-100% air as well as the minimum volumes of air required for complete combustion of pure hydrocarbon gases. The preparation of a certified natural gas for calorimeter calibration is described by Kniebas (67C).Clingman (2OC) describes a new method for the continuous measurement of the calorific value of gaseous fuels. The method is based on the relation between the calorific value and the ratio of air to natural gas. Gas chromatography is used by Gaeke (39C) for the determination of hydrogen in low pressure gas samples. Schwartz and Durbin (11OC) provide experimental data which show that spherical, attrition-resistant support materials, such as Pennzoil Support (PS) l, provide efficiency separations of C3-C4 alcohols. The paper by Purcell and Gilson (96C)summarizes the official NGPA-ASTM method used for natural gas analysis and recommends 3 advanced gas chromatographic methods and systems for the same application. Mallik and Khurana have made gas chromatographic studies on the variation of LPG composition during use
ANALYTICAL CHEMISTRY, VOL. 4 7 . NO. 5, A P R I L 1975
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and its effect on calorific value (76C, 77C). Calculations involving the comprehensive analysis of natural gas by chromathermography and gas-liquid chromatography are discussed by Narizhnaya (86C). The concentration of methane in methane or natural gas is determined by Ritchie and Kulawic (99C) using infrared spectrometry. One determination takes about an hour and the accuracy of the technique is similar to that of a method consisting of combustion, reduction, and mass spectrometry. Nitzsche, Waurick, and Maass (88C) have developed a technique for converting hydrocarbons into carbon dioxide for analysis by mass spectrometry. The potentiometric determination of trace amounts of carbon dioxide in gases has been studied by Blokh, Khyanina, and Maiorov (11C). Aidam and Kanneberger ( I C ) have obtained a patent on an apparatus for the quantitative analysis of gas mixtures using paramagnetic susceptibility. A critical evaluation of existing and future methods for the determination of hydrogen sulfide in natural gas is given by Radulescu (97C). An instrument has been developed by Gokhberg and Ovchinnikova (44C) to provide a direct, reactive gas chromatographic method for the determination of the moisture content in complex gas mixtures. Starshov, Ivanova, and Kovrova (116C) determine small amounts of moisture in ethylene and propylene by 4-5 hour percolation of the gas through absolute methanol and potentiometric titration of the methanol with Karl Fischer reagent. The coulometric determination of water in natural gas is described by Shorokhov (114C) and the maintenance of the sensing elements in the coulometric method is described by Klimushin, Lakeev, and Mikhailov (66C). Gokhberg, Podbornov, and Ovchinnikova (43C) monitor the moisture content of natural gas during drying with a UKh-2 chromatograph. Standard combustion data for the fuel gas industry have been provided by Armstrong, Domalski, and Minor (6C). Aviation Fuels. Gottshall, McAllan, and Robertson (45C) present a review on the historic development of jet fuels, their composition, and manufacture. Dark (24C) describes how modern high-speed liquid chromatographs can separate depentanized nonolefin-containing liquid fuels by class. Correlations have been derived by Siemssen (115C) between composition, smoke point, luminometer number, heat of combustion, and hydrogen content of a jet fuel and its API gravity and the aromatics content. Zhmykohova (129C) gives equations for the calculation of the smokeless flame height of kerosine distillates from their relative densities. Gas chromatographic data are used by Butler and Gootee (16C) and Butler and Martel (17C) to calculate vapor pressure, density, heat of combustion, aromatics content, unsaturates, and alicyclics, distillation range, smoke point, and freeze point of aircraft fuels. Petrovic and Vitorovic (93C) use the n-paraffin content obtained by gas chromatography to estimate the freezing point of jet fuels. The hydrogen content of fuels is correlated with smoke point, luminometer number, net heat of combustion, specific gravity, and aniline point by Martel (79C). A nomogram of pressure vs. boiling point of supersonic fuels is used by Chertkov and Kolobova (19C) to calculate the IBP and 50% point of standard jet fuels. The measurement of ethylene dibromide depletion in aviation gasoline is one criterion for the evaluation of the storage stability of coatings used for the corrosion prevention of fuel tanks and containers. Esposito (32C) offers an accurate, uninvolved procedure for measuring ethylene dibromide depletion. Lyashenko, Karetnikova, et al. (75C) determine nitrogen-base additives in jet fuel by adding 10 ml of chloroform and 40 ml of glacial acetic acid to a 200-ml 174R
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filtered sample and titrating with 0.02N perchloric acid with 5-6 drops of crystalline violet as indicator. A patent has been issued to Gureev, Tugolukov, Mardukhaev, Bobrovaskii, and Denel (48C) for a method measuring the tendency of aviation fuels to form a static electricity charge. Shcherbachenko, Ivanov, and Satin (112C) have devised a rapid method for the quantitative determination of water in fuel based on the interaction of water with standard aqueous methylene blue solution. A patent has been obtained by Menon, Srivastava, and Mehrotra (84C) for a compound to detect suspended free water in turbojet fuel. The compound contains cresol red and barium carbonate in a 1:lOO ratio and is packed in gelatin capsules. Menon, Srivastava, and Kochat (83C) have another patent for a moisture detecting device which consists of a filter paper coated with a 1:l mixture of FeS04, (NH4)2S04. 6 H 2 0 and K3Fe(CN)6. Astaf'ev, Englin, et al. (7C) have studied the kinetics of formation of oxidation products of drastically refined jet fuels. Edwards (31C) reports the results of a survey organized by the Institute of Petroleum to measure the precision of the ASTM-CRC Fuel Coker test. The Coordinating Research Council ( 2 l C ) has been requested by ASTM to develop research techniques for determining the oxidative stability of aircraft gas turbine fuels. The new technique is called the Jet Fuel Thermal Oxidation Test. Bert and Painter (9C) give additional information on this potential replacement for the ASTM-CRC test (ASTM D-1660). Copper and silver corrosion by aviation turbine fuels has been studied by Tripathi, Gulati, et al. (123C). Aksenov, Chernova, et al. (2C) have studied the effect of chemical composition of jet fuels on their antiwear properties. The ASTM D-1094 water reaction test and the ASTM D-2550 modified water separation index test have been used by LePera and Sonnenburg (72C) to study the water reactivity of gasolines, diesel fuels, and turbine fuels. Motor Fuels. Hammerich and Gondermann (49C) have made a review of spark-ignition fuels which includes compositions and additives, physical and chemical properties, test procedures, etc. A discussion on the nature and composition of gasoline is presented by Boldt and Griffiths (12C). Jenkins (56C) discusses the present practices and future possibilities for specification of product quality. Stavinoha and Newman (117C-121 C) have explored and evaluated gas chromatographic techniques for the hydrocarbon type analysis of gasoline. A rapid method for determining aromatics in gasolines has been developed by Vigalok, Tsybulevskii, and Vigdergauz (124C). Haynes (51C) describes an on-line data acquisition and processing computer system directly connected to gas chromatographs, to a high or low-resolution mass spectrometer, and to an emission spectrometer. Los Angeles 1970 gasolines have been examined by Mayrsohn and Bonamassa (81C) for the distribution of alkenes, alkanes, and aromatic hydrocarbons. A patent has been issued to Fenske and Sampson (35C) for a system of determining and controlling a composition characteristic while blending a multicomponent combustible fluid. The system is useful in making a wide variety of combinations of feeds to produce a fuel with the required octane number. The prediction of Reid vapor pressure from gas chromatographic data is described by Bradley and Kennard (14C) and DeBruine and Ellison (25C). Gas-liquid chromatography is used by Alary and Coeur (3C) for the determination of ethanol, methanol, ethyl ether, or nitromethane in motor fuels. A procedure for the determination of thiol-sulfur in
APRIL 1975
motor fuels is described by Busev, Teternikov, and Maslennikova (15C).The sample is shaken with saturated sodium acetate solution in ethanol-benzene and 2 to 3 drops of diphenylcarbazone indicator solution; the mixture is titrated with ethanolic 4-diethyl- or 4-dimethylaminophenylmercury acetate until a lilac color is produced. Grupe, Malinka, and Hentschel (47C) have obtained a patent for an accelerated storage test. The gasoline sample is dissolved in a mixture of 85% acetic acid in water, chromate(VI), sulfuric acid, and the decrease in chromate(V1) as a function of time is measured spectrophotometrically. The time required to reduce the amount of chromate(V1) by one-half is called the chromic acid number and is an index of fuel aging that compares well with long-time storage tests and the ASTM bomb test. Schwartz, Allbright, et al. (109C) have developed a correlation between gum formation a t 110 O F and oxygen absorption after 16-hour storage a t 140 O F in pressure-sealed glass bottles. Material Research Standards (80C) reports that ASTM Committee D-2 is working on methods to detect trace elements in gasoline. ASTM D-3231, Phosphorus in Gasoline, and ASTM D-3237, Lead in Gasoline by Atomic Absorption Spectrometry, are proposed for use by the U.S. Environmental Protection Agency according to the Federal Register (34C).Duffy (30C) reviews Amoco Oil Co. methods for determining lead in their entire motor fuel distribution system. Several methods are reported for preparing the gasoline sample for determination of lead by atomic absorption spectrometry. Mansell and Hiller (78C) use the Parr acid digestion bomb to decompose the tetraethyllead instead of refluxing the gasoline with hydrochloric acid. Hodkova and Holle (52C) add bromine solution to the gasoline sample until it shows a reddish brown coloration in the dark, then treat the sample with boiling nitric acid, and shake the cooled mixture with water before allowing it to separate into a hydrocarbon layer and an acid extract. Campbell and Palmer ( I 8 C ) extract the lead with aqueous iodine monochloride; boil to convert lead to a lead iodide complex; then reduce with ascorbic acid and re-extract lead as the complex iodide with 2-butanone. Kashiki, Yamazoe, and Oshima (60C) determine lead in gasolines by atomic absorption spectrometry after eliminating absorption differences among alkyl lead compounds and preventing tailing of the absorptions. Robbins (IOOC) determines lead in gasoline by heated vaporization atomic absorption spectrometry. Other methods of determining lead in gasolines are: the chelatometric indirect titration of the chloroform extract, by Garcia Escolar and Paz Castro (40C); the chelatometric direct titration of the hydrochloric acid extract by Forino (38C);the solid internal standard method for X-ray fluorescence spectrometry by Park and Bird (89C);and an oxygen bomb/alternating current polarographic method by Takeuchi (122C). Holding and Williams (53C) describe a rapid chemical procedure for the determination of trace lead contamination in nonleaded gasolines. This method has been developed for use by semi-skilled personnel under field conditions or in poorly equipped laboratories. It involves the colorimetric determination of lead via the dithizone complex formed with partially cleaved lead alkyls produced by the reaction of the gasoline sample with bromine. The Coordinating Research Council (22C) has published their analysis of 1971 road rating data. Keller and Rueckel (62C) report that Amoco’s R&D Department is using an electronic instrument for all normal determinations of road octane number by the Modified Borderline technique. A review of engine fuel test procedures is presented by Wilke and Wolf (127C).Pol’shinskii (94C)gives equations for calculating the octane number of gasolines from their density,
fractional composition, aniline point, and iodine number. An equation for calculating the front end Research octane numbers of gasoline blends from blend component data is given by Gruenwald and Blazejovsky (46C). A patent has been issued to Dolbear (29C)for calculating octane number from the allylic, olefinic, and aromatic H concentrations in gasoline. H is the total integrated resonant energy value for the designated constituents and is determined by nuclear magnetic resonance. Petroleum Times (92C) reports on a highly accurate reformer octane analyzer which can evaluate octane number over a range of 88-102 octane reformate. The system is based on chromatography. Anderson, Sharkey, and Walsh (4C) describe the derivation and use of linear equations for calculating Research octane numbers from composition data obtained by gas chromatography. The Research octane number of leaded gasoline reformates is calculated from chromatographic analyses of total aromatics by McCoy (82C). Antonik, Delfosse, and Baillet (5C) use the cold explosion limit of hydrocarbons or their mixtures to determine octane number. Trimethylpentane isomers have been analyzed by pyrolysis-gas liquid chromatography and a rectilinear relationship between the amount of the parent molecule degraded in the pyrolysis chamber and the Research octane number of the isomer has been established by Walker and Maynard (126C).Cunningham and Larson (23C) have been issued a patent on octane monitoring. Known amounts of air and gasoline are continuously mixed a t approximately 325’; the amount of oxygen consumed is measured and correlated to octane rating. Methods for the collection, storage, and analysis of internal combustion engine exhaust gases are presented by Konopczynski and Prasek (69C) and Seizinger and Dimitriades ( I I 1 C ) . A study of Dimitriades, Eccleston, et al. (27C) on the relationship between fuel composition and pollution characteristics shows that only polyalkylbenzenes correlate strongly with reactivity. Toxic emissions from gasoline additives are identified with the aid of a gas chromatograph and analytical procedures for organic hydroperoxides have been developed. Dimitriades, Raible, and Wilson (28C) have investigated the identification of components contributing toward each peak in the chromatograms of automobile emissions. The determination of carbonyl compounds in car exhaust gases is described by Papa and Turner (9OC).Dietz (26C) has developed a gas chromatographic procedure to determine phenols in car exhaust gases. The continuous analysis of reactive organics in car exhaust gases by selective combustion is described by Innes ( 5 9 2 ) .Fischer and Becknell (36C) have modified the Saltzman method for the determination of low concentrations of oxides of nitrogen in car exhaust gas. They use standard mixtures of NO and NO2 in place of the usual NaN02 calibration. A gas chromatographic method is used by Hauser and Pattison (50C) to study particulate combustion products from gasoline and diesel engines. Thiols in thiol-air mixtures are determined by Kirchner (63C)using a modification of the ASTM method for thiol-sulfur in aviation turbine fuels. Distillate Fuels. Several reviews appear in the literature. Diesel fuel economics, production, refining, additives, and analysis are reviewed by Kahsnitz (57C). The specifications, properties, and evaluations of fuel oils are reviewed by Kite and Stephens (64C). The diesel combustion process and general characterization of diesel fuels are outlined and 18 standard tests for evaluating properties are discussed by Kite and Pegg (65C).Rumpf reviews heating oils (102C) and kerosine (103C) covering properties, requirements, additives, and testing of properties. A review
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of Relyea (98C) covers the history of the diesel, dual fuel, and spark-ignition gas engines and related information. A differential gas chromatographic method which offers a rapid, reasonably precise, and simple technique for the determination of normal paraffins in kerosine is described by Folmer (37C). Postnov, Lulova, and Mikhailov (95C) determine the composition and percentage of n-alkanes in diesel fuels by gas-liquid chromatography. The effect of boiling point and chemical composition on the burning characteristics of high boiling petroleum fractions has been studied by Moriya (882). Shnaider (113C) has established a correlation between the cetane number of light catalytic gas oil and its sulfonatable constituents. A new analytical test for the detection of additive levels of nitrate-type cetane improvers in diesel fuel is described by Esposito (33C).The procedure employs a high temperature saponification followed by a sensitive spot test for nitrates. An evaluation of the ASTM-CRC luminometer as a laboratory technique to predict the combustion-improving characteristics of diesel smoke-supressant additives by LePera and Hartzell (73C) shows that this instrument cannot differentiate between different fuel or additive blends because of unsatisfactory reproducibility. Kajikawa and Kawaguchi (58C, 59C) have studied the relationship between color stability and nitrogen compounds of hydrorefined kerosine. A reduction in the time required for the titration determination of acid number is achieved by Ignatenko and Mashchenko (54C) using bromcresol purple as indicator. Gibbons, Metcalfe, and Rosborough (42C) determine vanadium and sodium in fuel oil by y-spectrometry with a Ge(Li) detector. The measurement of barium in petroleum products using a 2.8-MeV activation analysis shows potential for the routine determination of barium in petroleum additives according to an evaluation made by Landolt and Struckmeyer (70C).von Lehmden (71C) has evaluated analytical techniques for the determination of trace elements in fuel oil and gasoline. Non-destructive instrumental monitoring of fuel oil for vanadium, sodium, and sulfur is carried out by Persiana and Shelby (91C). Neutron activation is used for sodium and vanadium and X-ray analysis for sulfur and also vanadium. Ropars (101C) describes the determination of vanadium, sodium, and nickel in heavy fuel oil by atomic absorption spectrophotometry. Yutkevich and Minut (128C) recommend a modified atomic absorption spectrophotometric procedure to monitor the vanadium content of heavy fuels used in gas-turbine ships. Changes in chemical composition and physical properties of a heavy residual fuel oil weathering under natural conditions have been studied by Betancourt and McLean ( I O C ) . A patent has been issued to Saunders (104C) for a procedure for the determination of the water content of liquid fuels by infrared specta. Barrett, Hazard, McComis, and Locklin ( 8 C ) describe the design, construction, and preliminary combustion trials of rig to evaluate residual fuel oil/water emulsions. The dispersion of contaminating particles in fuels and oils as determined by Bol'shakov, Sibarova, and Timofeev (13C) is based on a small angle light scattering method that used a photoelectric multiplier as the light receiver. Loska, Janczyszyn, and Gorski (74C) optimize the parameters of a system for continuous activation analysis of liquids. The system has been applied to a solution of phenol in diesel oil. The pour point stability of residual petroleum fuels has been studied by Nikolaeva, Mitusova, and Demidenko (87C). Kawahara, Santner, and Julian (61C) can characterize heavy residual fuel oils and asphalts by infrared spectrophotometry using a statistical discriminant function analysis. Miscellaneous. Gerbaz and Del Ross (41C) have used 176R
thermogravimetry to study the thermal behavior of additives in cutting oils. The wear of the components of a hydraulic oil system has been assessed by Savunov (105C) using ultraviolet spectrographic determinations of iron, copper, lead, aluminum, chromium, and silicon in the oil. Koch, Schmitz, and Loose (68C) determine sulfur in solid and liquid fuels by X-ray fluorescence. Further development of the burning profile method for evaluating solid fuels by Wagoner and Winegartner (125C) shows that the method can be used in different laboratories with slightly different equipment to give similar results. Burning profile is defined as plots of the rate of burning vs. the temperature, as the temperature of the furnace is increased by 27 OF/minute.
Lubricants, Oils and Greases N. H . Fick Texaco Inc., Beacon, NY
Oils. Separation techniques and analytical methods, including liquid chromatography, infrared, membrane dialysis, molecular distillation, and X-ray fluorescence, for analyzing lubricating oils and additives were discussed by Fujita ( 2 6 0 ) . Ikuyama ( 3 4 0 ) reviewed analytical methods for lubricant analysis and Zerbe ( 1 0 7 0 ) discussed spectrometric techniques for identifying additives in oils. Stanescu and Baliu ( 8 9 0 ) used infrared spectrometry to identify dispersant succinimide type oil additives. Infrared techniques and Watermann analysis were employed by Anand et al. ( I D )to determine molecular structure of sulfonates used as dispersants in motor oils. Tooke ( 9 1 0 ) applied infrared to determine carbon type analysis of lubricating oil base stocks by measuring extinction values a t 6.2, 12.3, and 13.9 wm. Contents of aromatic and paraffinic carbon were calculated with naphthenic carbon being obtained by difference. Trawinski ( 9 3 0 ) developed equations for structural analysis of lubricating oils based on infrared absorbance at several wavelengths and reported correlation with results calculated from n-d-molecular weight determinations. The advantages of various analytical methods for structural group analysis were discussed by Oelert and Hemmer (630). Lubricating oil additives including dialkyl dithiophosphate, phenate, sulfonate, and polymethacrylate were detected in mixtures by Muntean and Halus ( 5 7 0 ) using infrared spectrometry. Ohls et al. ( 6 4 0 ) developed a method to identify traces of lubricants extracted from steel based on a comparison of infrared total-reflectance and transmission spectra. Infrared was applied by Sato et al. ( 7 6 0 ) to detect mineral oil contaminants in vegetable oil/water mixtures used in forging operations. The ratio of intensity of absorbances a t 1750 cm-' due to vegetable oil carbonyl groups and 1460 cm-1 due to mineral oil methyl and methylene groups was used to calculate concentration of the mineral oil. Techniques for analysis of lubricating oil additives by thin-layer chromatography were advanced by several investigators. Morot-Sir ( 5 4 0 )developed methods for determining phenol and amine antioxidants, zinc dithiophosphates, and sulfonates. Multistage chromatogram development was used by Ligezowa and Lason (450) for separating sulfonate and succinimide dispersing agents and salicylate detergent additives. Dovgopolyi ( 2 2 0 ) used thin-layer chromatography to determine antioxidant additives in transformer oils. A second stage of elution was required for a-naphthol and
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5 , APRIL 1975
(1020) studied particulate contaminants in hydraulic 0-naphthol. This method was modified by Lipshtein et al. ( 4 6 0 ) to determine Ionol (2,6-di-tert-butyl-4-methylphe- fluids and developed a method to provide a complete contaminant profile. A review covering techniques of particle nol) in transformer oils by substituting silica gel coated size analysis of mineral oils was presented by Jaeger et al. aluminum foil in place of the alumina coated glass plates (350). used by Dovgopolyi. For the separation of polycyclic hydroThe carcinogenicity of various petroleum fractions was carbons and benzothiophenes in used engine oils, Lloyd the subject of a review of Catchpole et al. ( 1 4 0 ) .Methods ( 4 7 0 ) employed solid-liquid chromatography. Vaughan et of analysis for the known carcinogen benzo[a]pyrene were al. ( 9 6 0 ) performed the same analyses using pressure asgiven for concentrations down to 0.02 ppm. Low temperasisted (650 psi) stainless steel columns packed with Corasil/ ture differential scanning calorimetry was employed by CIS. The technique was intended primarily for the forensic Noel (59D) to define the waxy components of lubricating fingerprinting of engine oils. Kichkin et al. ( 3 8 0 ) defined various features of the oils. Staffehl et al. ( 8 8 0 ) reported on the determination of potential sludge formers in motor oil base stocks by meastructure of commercial polyisobutylenes by nuclear magsuring the absorption in the ultraviolet at 325 nm. A nomonetic resonance and showed the effect of structure on propgraph for determining the molecular weight of lubricating erties of oils thickened with 5-20% of the polymer. An NMR method was developed by Bormann and Deutsch oils based on evaporation loss measurements by ASTM D ( S D ) ,based on the -0-CHz- band intensity a t 6.08 ppm, to 972 was described by Zanker (1030). determine concentration of polymeric ester pour point imOn the subject of test methods for automotive engine provers in wax precipitated from petroleum products a t crankcase oils, Minami ( 5 3 0 ) and Schilling ( 7 7 0 ) presented surveys covering American and European classification low temperatures. The analysis of nitrogen-containing polymeric ashless oil systems and the gasoline and diesel engine tests used for compliance. Minami’s survey included the current situadispersants by dialysis was carried out by Care1 ( 1 3 0 ) .The tion in Japan. Rodgers and Gallopoulos ( 7 3 0 ) reported on diffusate was further separated on a column of alumina a rotary engine test to evaluate lubricants for control of while the active high molecular weight compounds rerotor deposits. The test, which utilizes a Mazda 10A rotary mained in the dialysis concentrate. Klevtsova et al. ( 4 0 0 ) engine operated at 5000 rpm for 100 hours on a dynamomeperformed similar analyses on alkylphenolate, sulfonates, ter stand, ranked lubricants in the same order as vehicle and alkenylsuccinimide type additives using doctor’s finger tests. An engine test procedure to evaluate oil thickening sheaths as dialysis membranes. under severe high-temperature conditions was described in For the analysis of sulfonate-type motor oil additives, a paper presented by Wilson et al. (1010).The test utilizes Fialko and Balashova ( 2 5 0 ) carried out hydrolysis in cona Petter W1 single-cylinder engine. Cecil ( 1 5 0 ) developed a tact with cationic sulfonated polystyrene resin in an ion exbench test method to measure high temperature thickening change column and discussed the advantages over conventendencies of motor oils. The test correlates with the MS tional aqueous acid hydrolysis. Brewer ( 1 0 0 ) determined Sequence IIIC engine test on a pass-fail criterion based on oil-soluble sulfonates in lubricating oils by two-phase titration with Hyamine 1622 in sulfuric acid and chloroform. less than 400% viscosity increase after 40 hours. Results of Metal carbonates do not interfere. Langanke ( 4 4 0 ) devela piston ring and cylinder scuffing study were reported by oped ion exchange techniques for analysis of fuel and lubrithe Motor Industry Research Association ( 9 4 0 ) .The projcant residues on engine parts. Zatka (1050, 1060) develect consisted of rig testing, engine testing, and surface finoped rapid chelatometric methods for successive determiish survey. Schmidt ( 7 8 0 ) correlated wear measurements nation of zinc and phosphorus in additives. Similar techin internal combustion engines, wear testing machines, and niques could also be applied to cobalt-phosphorus and barmetal-forming processes by the ratio of linear wear to linium-phosphorus combinations. Norwitz et al. ( 6 1 0 ) found ear friction surface. the usual ASTM methods for determining phosphorus in Baniak and Fein ( 4 0 ) reviewed ASTM bench-type E P petroleum base lubricants did not apply to sebacate base and antiwear tests and the correlation of Four-Ball and lubricants and described titrimetric, gravimetric, and specTimken test data with performance tests for various gear trometric methods that were satisfactory. Elliott et al. types. In an investigation utilizing various friction testing ( 2 3 0 ) reported on a cool-flame emission method for phosmachines, Gruenwald ( 3 1 0 ) studied the interrelationship phorus in lube oils based on measurement of emission of of physical and chemical reactivity of oil, micro-geometry HPO at 528 nm in a cool H-N diffusion flame. The simulof the metal surface, and test conditions of time, sliding vetaneous determination of sulfur, chlorine, phosphorus, and locity, load, and temperature. Bailey and Cameron ( 3 0 ) zinc in gear oils and additives by X-ray fluorescence was devised a modification of the Four-Ball tester wherein the discussed by Fujita and Yamauchi ( 2 7 0 ) . The necessary nest of three balls was replaced by three flat-ended 0.187corrections for interfering elements were included. in. long by 0.187-in. diameter pegs. A microscope was arThe measurement of micro-dispersed particles in lube ranged to observe the three tracks in the top ball. Harting oils drew the attention of several investigators. Overbased ( 3 2 0 ) reported on a 14-laboratory cooperative study of the additives consisting of micro particles of inorganic carbonprecision limits of the Timken tester. The derived precision ates stabilized by oil soluble metal sulfonates were studied limits were found to be considerably wider than those reby Riegelhuth and Watkins ( 7 1 0 ) by electron microscopy ported in the ASTM D 2782-71 standard. A review of facemploying freeze-etching techniques. Schmitz ( 7 9 0 ) develtors affecting the reproducibility of the Timken test was oped methods to determine particle size analysis of oil sampresented by Culp and Lieser ( 2 0 0 ) . A special low-cost ples with a Coulter Counter. To avoid problems involved in fixture for the LFW-1 Tester, which permits EP and wear using oil samples directly on the Coulter Counter, the oils evaluation of as little as 0.5 ml of lubricant, was described were first filtered through a membrane filter and the partiby Gardos and Jones ( 3 0 0 ) . cles were transferred to electrolyte solutions ultrasonically In an investigation of mass transfer in the wear process, or by dissolving the membrane. A method for determining Capone et al. ( 1 2 0 ) mounted an isotopic X-ray fluoresparticle size of contaminants in the 2-100 p range in fuels cence apparatus detector on a pin-and-disc machine so as and engine oils by light dispersion a t low angles of incito observe the tracks laid down by the lead, zinc, and copdence was reported by Bol’shakov et al. ( 8 0 ) . Wilson per specimens sliding on a steel disc. Mecklenburg ( 5 0 0 ) A N A L Y T I C A L CHEMISTRY, V O L . 47. NO. 5 , APRIL 1975
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studied forces in the Falex machine and concluded there were differences in normal loads and in frictional forces between the faces of each Falex vee block during pin rotation which resulted in higher loads on the incoming faces causing greater wear on these faces. Miller and Mackenzie ( 5 2 0 ) described a novel slidingholling contact test device which utilizes annular rollers rotating on locating spigots. The device overcame problems involving alignment and vibration and gave excellent reproducibility. An apparatus for testing lubricating properties of fluids and bearing materials operating in the metahydrodynamic regime was described by Vinnicombe ( 9 7 0 ) .A new method for measuring contact potential differences based on the determination of changes in the electron work function for two metals was proposed by Kichkin et al. (390). Good correlation was found in comparing initial results with antiwear properties of several oils as determined by a friction test machine. On the subject of E P gear oils, Papay ( 6 6 0 ) presented a paper which reviewed gear oils and additives currently in use and the tests used to evaluate them. Using the (German) FZG Gear Test machine, Richter ( 6 9 0 ) compared spur and hypoid gear velocity and load ratios and demonstrated the greater difficulty of lubricant film formation on hypoid gears. Richter ( 7 0 0 ) also conducted scuffing tests on several mineral and synthetic oils using both spur and hypoid gears and found a linear correlation with both types of gears indicating the tests were equivalent. Seitzinger ( 8 1 0 ) described an L-42 test procedure, utilizing the FZG Gear Test machine, which corresponds to the Americ CRC L-42 Axel Test. Results on eleven oils tested showed good agreement with the CRC L-42 test. A multipurpose planetary gear testing machine capable of measuring oil film thickness while the gears are in operation was reported by Kasuba and Radzimovsky ( 3 7 0 ) . Film thickness measurement was based on an electrical discharge occurring when the film became thin .enough for electrical breakdown. An experimental involute gear drive test machine operating under conditions of extreme boundary lubrication, described in a paper by Radzimovsky et al. ( 6 8 0 ) , was capable of giving instantaneous efficiency and coefficient of friction data. Westlake and Cameron (1000) presented a paper describing a new point contact instrument for measuring central and minmum film thicknesses of fluids. Chitty ( 1 6 0 ) developed a device for determining ability of oil to lubricate the valve control mechanism in motor vehicle engines. The device makes use of commercial cams and lifters and incorporates accurate control of oil temperature, cam load, speed, and other test conditions. Several investigators applied differential thermal analysis in determining thermo-oxidative stability of oils. Commichau (180) studied mineral and synthetic oils and discussed applications and limitations of this technique. Ermolaev et al. ( 2 4 0 ) studied behavior of oils in a derivatograph, an apparatus which records curves of differential thermal analysis, thermogravimetric measurement of weight loss, and rate of weight loss, all in one operation over a temperature span of 0-1200 "C. A combination of differential thermal analysis, chromatography, and mass spectrometry in an air stream was employed by Bogdanov et al. ( 7 0 ) to study thermo-oxidative stability of polymeric additives. A report by Cuellar and Baber ( 1 9 0 ) described procedures to test MIL-L-7808 type lubricants for oxidati? corrosion, and deposition characteristics in a glassware apparatus. Development of a light meter device for measurement of glassware deposits was described. Martynova et al. ( 4 9 0 ) reported marked reduction in testing time required to reach the same level of acid number when testing ther178R
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mal oxidative stability of oils by UV irradiation under a mercury vapor quartz lamp a t 150-200 "C compared to a more conventional method. The influence of irradiation from a 6oCosource on friction torque characteristics of oils was studied by Zaslavskii et al. (1040) in a specially designed test rig which provided continuous recording of torque under conditions of hydrodynamic lubrication. The shear stability of multigrade motor oils was the subject of a paper by Smith et al. ( 8 4 0 ) who reported results obtained by several laboratories in four types of bench tests and three different engine tests on 13 oils. The engine tests correlated better than the bench tests in predicting viscosity changes in field tests. Talbot e t al. ( 9 0 0 ) reported on development of a simple inexpensive engine test based on an electric motor driven single cylinder lawnmower type engine. Excellent correlation was obtained with Chevrolet V-8 engine test results. A comparison of several bench tests in Europe for determining shear stability of polymeric additives was conducted by Del Ross et al. ( 2 1 0 ) . The Bryce injection valve was found to be more reliable in predicting viscosity loss than a sonic oscillator device or the FZG gear test machine when compared to results of a field test using a Fiat 124 passenger car. Morton (560) surveyed cutting fluids and included a discussion on the application of short term bench tests and design of workshop tests with commercial machine tools to evaluate various types of cutting fluids. In a later review, Morton ( 5 5 0 ) covered tests for soluble oils including storage stability, emulsification, foaming, corrosion, staining, and bacterial contamination. Various aspects of drill and tap testing for cutting fluid evaluation were discussed by Russell ( 7 5 0 ) .In a paper describing an ASTM round robin test program to evaluate cutting fluids, Blanchard and Syrett ( 6 0 ) ranked several additive types in general order of effectiveness but concluded that the tapping torque, drilllife, and lathe tests were not in agreement. The biological testing of cutting fluids, the advantages and weaknesses of laboratory tests, the effectiveness of bacteriastats to prevent emulsion instability, and the need for predictive standard biodegradability tests for effluent water quality were discussed in a paper by Bennett ( 5 0 ) . In a study of the relationship between biodegradability of oils and their hydrocarbon content, Krein et al. ( 4 2 0 ) found that resistance of oils to microbial action decreases with increasing refining severity. Brink ( 1 1 0 ) presented a review covering various types of fire-resistant hydraulic fluids, bench and pump tests for determining flammability and wear properties, special tests for emulsion stability and rusting, and applications in the metal and coal mining industries. Shombert ( 8 2 0 ) discussed electrical testing of transformer oils, limitations of ASTM methods D 877 and D 1816, and possible causes of dielectric breakdown of transformer oils. Watkins ( 9 9 0 ) improved the precision of the ASTM D 892 Foam Test by altering the cylinder configuration. A new method for measuring air release tendencies of oils was developed by Rowland et al. ( 7 4 0 ) . Air was entrained by stirring and air release was determined with the aid of a photocell. Pace ( 6 5 0 ) developed a centrifuge modification of the ASTM D 2619 Hydrolytic Stability Test to permit its use with fluids with specific gravity near that of water. A study of the volatility of lubricating oils in vacuum, mm Hg, was carried out by Klimov et al. (410). Greases. A broad discussion of applications of infrared spectrometry to analysis of additives used in lubricating grease was presented by Marino et al. ( 4 8 0 ) . Functional groups detectable by infrared, sample preparation, and elimination of interferences were covered and sample spec-
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
tra were given for 27 additives commonly used in greases. Fuks et al. ( 2 9 0 ) reviewed use of infrared spectrometry for studying the properties and composition of greases including identification of synthetic base oils, formation of oxidized products in service, temperature-induced phase conversions, and evaluation of grease behavior on metal surfaces. The concentration of molybdenum disulfide in greases was determined by Fujita and Yamauchi ( 2 8 0 ) by measuring the intensity of the Mo K a line by X-ray fluorescence. A colorimetric method for determination of trace quantities of nickel in greases was developed by Ssekaalo ( 8 7 0 ) . Dimethylglyoxime was used to form a complex which was extracted with chloroform for absorbance measurements a t 329 nm. Kantor and Major ( 3 6 0 ) described a derivatographic method to delineate the manner in which water is bound in calcium based grease. Extensive reviews of all types of lubricating greases, their processing, composition, testing, and use were given in papers by Schultze and Goettner ( 8 0 0 ) and Lane ( 4 3 0 ) . Roberts ( 7 2 0 ) reported results of testing a variety of greases in helical gear units. Two simple laboratory tests, a 1000-hour oven test and a lubricity life test, were found to adequately screen greases for testing in the gear unit. A method which shows promise to differentiate E P properties of greases by the Four-Ball tester in a shorter time than the conventional ASTM D 2596 method was reported by Sibilia ( 8 3 0 ) .In a paper covering a cooperative test program to determine E P qualities of five lithium soap greases, Nordmeyer and Trettin ( 6 0 0 ) concluded that these machines are useful for screening purposes only and that the Four-Ball tester gave more consistent results than the Timken tester. The testing of greases to determine starting and running torque, low temperature characteristics, noise, and ability to lubricate under conditions of fretting was covered in a paper by Clark ( 1 7 0 ) . Low temperature characteristics of greases were also investigated by Spengler et al. ( 8 5 0 ) who measured torque during startup and steady-state operation of an axially loaded journal bearing from -70 to +77 “C. Spengler et al. ( 8 6 0 ) conducted low temperature tests on six greases in the KSM loaded ball bearing machine and concluded greases with synthetic bases gave better results than greases with mineral oil bases. A comparison of grease life and torque in roller bearings was studied by Armstrong and Lindeman ( 2 0 ) . On the subject of oxidation stability of lubricating greases, Tosonev et al. ( 9 2 0 ) described a study comparing several techniques including UV irradiation and two copper catalyzed procedures. The oxidation behavior of lithium 12hydroxystearate greases was investigated by Trillo et al. ( 9 5 0 ) using standard ASTM D 942 and D 1402 apparatus. The use of powdered metallic copper and oil-soluble copper catalysts in the D 1402 procedure shortened testing time while still differentiating adequately with respect to composition. Several investigators used infrared spectrometry to monitor the extent of oxidation in grease tests. T o evaluate antioxidants, Pencheva and Tsonev ( 6 7 0 ) followed absorption of the 1720 cm-’ band during aging of calcium soap greases under UV irradiation from a quartz lamp. Similar work was reported by Medvedeva and Fuks ( 5 1 0 ) who compared effects of exposure of greases to UV irradiation with oxidation deterioration during use in roller bearings. A combination of infrared and thermogravimetric technique was employed by Novoded et al. ( 6 2 0 ) to determine the thermo-oxidative stability of several calcium soap greases. A grease testing machine developed by Mecanique Et Entreprise Laboratoire ( 5 8 0 ) was reported to be capable of
determining the dynamic dropping point and high temperature stability of lubricating greases. Harting ( 3 3 0 ) reported on a new method of measuring grease consistency a t temperatures up to 700 OF. The method, which has been proposed as an ASTM standard, utilizes a Brookfield viscometer attached to a trident probe spindle immersed in a grease sample heated in an aluminum block. The current status of NLGI Reference Systems A and B was covered by Waring and Fischer ( 9 8 0 ) .Test results for Batch 2 of each system were given including repeatability and reproducibility values.
Wax D. R. Cushman and J. W. Schick Mobil Research and Development Corporation, Paulsboro, NJ
Thermal Analysis. For the period covered by this report, five papers dealt with thermal methods of analysis. Flaherty ( 4 E ) made a differential scanning calorimetric (DSC) study of hydrocarbon and natural waxes, including beeswax, and showed differentiation of ester-containing waxes. Giavarini and Pochetti ( 6 E ) also used a DSC technique to characterize paraffin and microcrystalline waxes (plus oils and bitumens). Their technique made it possible to determine waxes in crude oils and fractions more rapidly than by conventional methods. Hersh (IOE) used differential thermal analysis (DTA) to analyze paraffin or microcrystalline waxes, greases, polymers, antioxidants, hot melts and blends, and correlated results with chemical reactions such as oxidation. Sharpe and Wheals ( 2 4 E ) characterized candle waxes by DTA, and discussed thermograms for paraffin wax, beeswax, and “stearin”. Boelter ( I E ) used a related procedure, thermogravimetry, to study low molecular weight paraffins, microcrystalline waxes, Fischer-Tropsch waxes and polyethylene paraffins. The low molecular weight hydrocarbons were clearly distinguished from each other. Chromatography. Rincker and Sucker (19E) described gel and gas chromatographic methods for determining the paraffin-isoparaffin ratio and molecular weight distribution for five petrolatums. Postnov, Mikhailov, and Lulova (17E) analyzed solid paraffins by a chromatograph with a flame-ionization detector. Standard reference samples were used, with a graph of retention temperature vs. number of carbon atoms in the individual n-paraffins. Marschner and Winters ( 1 4 E ) analyzed four ozocerite samples by gas chromatography. They are waxy organic materials containing 80-95% n-alkanes. Possible explanations for the predominance of even-numbered alkanes a t high chain lengths are discussed. Shevchenko and Chernozhukov ( 2 5 6 ) determined the composition of n-paraffins in Carpathian ozocerites, by a chromatographic technique. The n-paraffins (from heneicosane to nonatriacontane) represented concentrations up to 6.5% of the ozocerites. Fal’kovich ( 3 E ) separated straight-chain hydrocarbons from paraffin wax by adsorption of calcium-A zeolite. An isooctane solution of the wax contacted the zeolite a t 150-300 “C, after which the zeolite was washed with n-heptane to recover the adsorbed hydrocarbons. Spectrometry. Popova and Baibazarov (15E) determined the oil contents in gatsches and paraffins spectrophotometrically a t 230 and 252 mm. The method had a lower compositional effect than existing methods. Guseva and Leifman ( 9 E ) studied high molecular weight paraffins of solid petroleum fractions by infrared spectrometry, and
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determined the average number of Me groups. Rincker and Sucker (20E)analyzed 28 petrolatums and their isoparaffin fractions by structure group spectrographic methods, and reported infrared and NMR data for 5 petrolatums and isofractions. Ratnasamy, Anand, and Gupta (18E) investigated the structure and properties of microcrystalline waxes by X-ray diffraction and IR spectrometry. Three series of tank bottom waxes showed correlation of CHZ/Me ratios and crystalline parameters with physical properties within each series, although variations existed from one series to another. Urea Adduction. Fal’kovich, Lukashevich, et al. ( 2 E ) analyzed a paraffin wax by complexing with urea. The four fractions were contacted with calcium-A zeolite (in isooctane solution) and desorbed with n-heptane. Molecules with side chains other than a t their ends can form urea complexes but cannot enter the zeolite pores, indicating that adsorption on zeolite is more accurate. Seleznev, Pavolv, Desyatova, Lyul’ko, and Stepanova (23E) used a rapid method of complexing paraffins with urea. The paraffins, urea, petroleum ether, and alcohol were mixed, filtered, washed with petroleum ether, and dried under vacuum a t 70’. Sochevko and Lukashevich (26E) studied the physicomechanical properties of ten paraffin waxes, ceresin waxes, and mineral waxes, all of which form complexes with urea. Brittleness and resistance to deformation were correlated with the amount of complexed components. Test Methods. TAPPZ (28E) reported a proposed reclassification of TAPPI method T659su-67 for determination of peroxide number of petroleum wax as a standard method. TAPPI (29E) also proposed a revision of TAPPI method T405ts-63 (ASTM D590) as a TAPPI suggested method. The method covers the determination of petroleum wax in impregnated paper, by extraction with trichloroethane. Glukhov, Lapitskaya, et al. ( 7 E ) recommended an improved method to determine acidity of paraffin. The method, GOST 5985-59, is based on titration with potassium hydroxide in the presence of nitrosine yellow. Popova and Ivanov ( 1 6 E ) described a rapid and simple method for the determination of melting points of solid paraffin, waxes, and fats. Kozlova, Ushatinskaya, and Demkina ( I I E ) improved the test for 3,4-benzopyrene in paraffin wax used in the food industry. The determination, from luminescence spectra of an n-octane extract of the wax, was improved by adjusting the concentration of the standard benzopyrene solution, and using a stronger mercury quartz excitation source. Miscellaneous. Seven papers dealt with subjects of general interest, or subjects not covered by the above classifications. Schuenemann (22E) gave a review on solid paraffin, with sixty references, covering definition, occurrence, production, properties, uses, and tests. The same author ( 2 I E ) reviewed petroleum waxes (mineral wax, petrolatum, paraffin) and mortan wax, with 45 references. Gottshall and McCue ( 8 E ) reviewed petroleum waxes, including petrolatums, with three references. Surface coating applications, replica making, polishes, electrical insulation, and other uses are discussed. Methods for determining physical and chemical properties of wax and functional properties of wax coated surfaces are outlined. Szergenyi (27E)classified petroleum paraffin waxes according to physical and chemical properties and listed standard methods for testing, including those for functional properties. Gerasimov and Topalova ( 5 E ) reported on the fractional crystallization of ceresins from Dolnodubnik petrolatum. They used a mixture of acetone, benzene, and toluene, also other solvents (methyl ethyl ketone-benzene, dichloroethane-benzene, and acetone-benzene). The ceresins were purified by pass180R
ing through silica gel. Kuliev, Kevorkova, and Anisimova (12E) also used fractional crystallization to characterize waxes and ceresins from Sangachaly crude oils, with acetone-toluene as solvent. The distillate portion (at 17% wax) and the deasphalted portion (at 34% petrolatum) were fractionally crystallized to yield various melting point waxes and ceresins. LeRoux and Dry (13E) investigated the distribution of branches and the mechanism of branching of Fischer-Tropsch waxes. A statistical calculation of concentrations of various alkanes to be expected in FischerTropsch products from the degree of branching and molecular weight was compared with published analytical results, and used to predict a hard wax composition.
Asphalt Herbert E. Schweyer Department of Chemical Engineering, University of Florida, Gainesville, FL
As in previous reviews, a large proportion of the research work has been related to the composition of asphalt. The number of publications has been so great that it is thought desirable to group the composition work into separate types according to the nature of the work. Gel Permeation and Chromatography. Most all separations of asphalt into its constituitive components rely on some type of preliminary separation in which gel permeation and chromatography, usually liquid, are the most commonly used. The fractions obtained are then usually further analyzed by the use of special techniques such as infrared spectrometry, nuclear magnetic resonance, and so forth. There has been a great activity in this area of work on asphalts in attempting to delineate the generic groups that are present, as well as in some cases attempting to actually establish the chemical form of the generic groups. The recent activity in these areas appears to be concentrated among foreign investigators. Likhotop (2F) studied the separation of asphaltenes by fractional precipitation and investigated the physical chemical properties of the precipitated material. Kats et al. (53F)used a microchromatographic method to separate the oil fraction from bitumen for study during oxidation. Kolbin et al. (56F)studied the separation of petrolenes from asphalt. Maltenes from different crudes were stated to be similar as evaluated by luminescence analysis. Hayes et al. (43F) used gel permeation chromatography on a soft Venezuelan bitumen with the fractions being characterized by NMR, IR, UV, and mass spectrometry. The gel permeation chromatography was also used by Meiris (64F) for the analysis of tar-bitumen mixtures. Greben (33F) suggested the use of luminescence analysis for study of micro amounts of bituminoides with glacial acetic acid and hydrogen peroxide as a mobile phase. Numerous investigators have attempted to delineate the chemical structure of asphalt using various preliminary techniques. Ratovskaya (82F) studied an Arlan petroleum and used precipitation chromatography for analysis of the physical chemical properties of asphaltenes. In addition, vanadium porphyrins and the distribution of sulfur were investigated. Budnikov and Pasternak (9F) studied the use of emission spectroscopy for trace elements and compared the results with polarographic methods. Bereznikov and Fedosova (10F) used quartz sand and gradient elution with benzene and hexane for recovery of fractions. Bikbaeva et al. ( I I F ) investigated the composition of crude petroleum asphaltene fractions by stepwise precipitation to produce 9
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fractions whose chemical structure was discussed. Budnik and Gun ( 1 6 F ) discussed Tatar and western Siberian crude residua and their oxidation products for their aromaticity and sulfur distribution. Others who have studied the chemical nature of asphaltic residues have been Budnikov and Medyantseva (I 7F) who investigated the vanadium and nickel content by polarographic methods. The degree of paraffinicity of asphalt was studied by infrared analysis by Lopienska and Smarzynska (63F).Phosphorus and sulfur in asphalts were studied by X-ray fluorescence spectrometry by Motoyasu and Oshima. Tanobe (69F) discussed the analysis of asphalts for weak and very weak acid content. Petersen et al. (77F) discussed the tentative identification of carbostyrils and their association complexes in the infrared spectra of asphalts. Yen (109F)has continued his work with model development of the structure of the heavy ends compounds in petroleum with the use of diagrams and tables. In another paper (108F), Yen has discussed further results of his work with electron spin resonance and the structures that he has proposed. NMR, IR, UV, and ESR. Although many of the methods mentioned in the preceding section do use the various techniques under the heading for this section the following papers have been selected as perhaps being more significant in this regard. Neumann ( 6 F ) selected resins for special study by means of IR, UV, and fluorescence spectrometry. A number of investigators have been looking a t the o oxygen bonding and its appearance in the IR spectrum upon oxidation of asphalts in order to study the changes that have occurred. Barbour and Petersen ( 8 F ) have discussed hydrogen bonding in this connection. Glotova and Kupershmidt (35F) have also studied this particular effect and included the IR absorption frequency a t certain wave lengths after oxidation in the presence of ultraviolet light. This work was amplified by Glotova et al. (36F, 37F).Kawahara et al. (54F)used infrared measurements with a statistical analysis for identification in the characterization of heavy residual petroleum products. Nuclear magnetic resonance was used by Speight (99F) to study the structure of asphaltenes from the Athabasca tar sand, and in a companion article the same author (98F) discussed the application of mass spectrometry to the Athabasca asphaltene. Pichler and Herlan (79F) reported on an application of mass spectrometry to the study high temperature coal tar which has some application for asphalts. Bronfin (14F)has reported on the uses of nuclear magnetic resonance studies of the structure of resin-asphalt substances and discusses the distribution of the methylene group. Similar NMR studies were reported by Cetner and Wachal (20F)for studies of the structure of asphalt and asphalt-tar substances. In addition to the ratio of aromatic hydrogen to aliphatic hydrogen, these authors also report on the corner carbon atoms and the degree of substitution of them. In a series of articles, Zalka (llOF-112F)has reported certain composition studies on asphaltenes that had been extracted with hexane and the solution used in a chromatographic column to provide separations. The eluents from the column were then separated by urea derivatives and further subjected to molecular distillation. The products from preceding operations were studied by means of IR, UV, and NMR spectrometry and molecular weights and elementary analyses were made. Petrov et al. (78F) also used elemental analysis and infrared spectrometry to compare the composition of tars and asphaltenes. Similarly Pearson (75F) studied the chemical structure of petroleum and coal tar pitch by the use of nuclear magnetic resonance. Sanada (86F)also studied the structural parameters
of petroleum pitches from a Khafji crude oil by densimetric, IR, and NMR methods. The same author also published a review of various analytical methods on the composition and structure of heavy oils (8%’). Both the latter articles are in Japanese. Electron spin resonance studies of bitumen have been reported by Yen (107F)in which a discussion is given on bitumen free radicals. Miscellaneous Composition Studies. The remainder of this study on composition relates to various isolated papers in which composition is the major part of the discussion. The use of tritium-labeling in study of asphalt photooxidation reactions has been discussed by Oliver and Gibson (74F).I t was pointed out that most of the water soluble products of photooxidation are derived from the lower molecular weight fractions of the bitumen. The use of ultracentrifugation in studying the molecular weight distributions of Kuwait asphaltenes was presented by Reerink and Lijzenga (84F)and it was pointed out that air blowing of the asphalt produced a widening of the molecular weight range present. Bamberg ( 5 F ) discussed results of fluorescence studies on the resins from certain crude oils and asphalts. The use of an Abbe refractometer with infrared light as a means of characterizing asphalts was studied by Wachal (I06F) using several asphalts dissolved in mineral oil. Bronfin e t al. ( 1 5 F ) studied the adsorption properties of asphaltene from certain Russian petroleums for naphthenic and paraffinic hydrocarbons in order to measure their peptization power. Sontowski (97F)discussed the microscopic structure of asphalt and the relationship to the peptizing power of the resin fraction. The problem of structure formation in asphalts was also investigated by Gurarii and Kolbanovskaya (42F)using synthetic mixtures of asphaltenes derived from several sources and various types of oils. Another study of peptization of petroleum asphalts was made by Stern (103F)using electrical-osmotic methods for evaluation. Kurbskii and Abushaeva (60F) reported on the composition of the bitumen from the Shugurovskii deposit. The bitumen represents approximately 4.75% of the sands and is apparently rather resinous in nature. Bodan et al. (12F)reported on some studies of the residual after molecular distillation which had a relatively high adhesion as derived from a high paraffin type tar which is attributed to an accumulation of asphaltogenic acids. Air Blown Asphalts. There were a number of papers relating to air blown asphalts which have been separated from the other listings. Costantinides et al. ( 2 3 F ) has discussed methods for studying the aging resistance of air blown asphalts based on IR absorption measurements. Nakajima (67F)reported on a study of air blowing of asphalt and discussed changes in the activation energy of liquefaction as related to the asphaltene content. Knotnerus ( 5 5 F ) reported on the measurement of oxygen absorption by bitumens in the light and dark and noted that oxidation inhibitors did not have any great effect in bitumen oxidation. The importance of free radicals being present was noted. Costantinides (25F)reported on evidence relating to the coagulation structure formed in blown asphalts and their aging characteristics. Akhmetova and Glozman ( 1 F ) reported on the difference of air blown asphalts produced in a continuous and intermittent operation. The compositions were measured and the properties compared which indicated that continuous oxidation produced a better asphalt property. Ivanyukov et al. (49F)reported on the oil removal and the effect of the properties of asphalt when oxidized in the presence of ferric chloride. Air blown asphalts produced by oxidation of western Siberian crude residues were reported by Gun et al. (40F).
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Kudryavtseva and Rozental (59F) reported on changes in composition that result when using ferric chloride as an additive during the oxidation of bitumen. In particular, their studies were pointed toward the composition of the oily portion of the bitumen. Graalmann (38F) reported on the water vapor permeability of air blown asphalts and asphalts containing various additives. Kudryavtseva and Rozental (59F) studied the oxidation of asphalt with ferric chloride as an additive. The work was directed toward the effect on the oily component on the bitumen. Pyrolysis of Asphalts. A number of studies have been reported upon the degradation of asphalts by heating with analysis of the degradation product. Chernova et al. ( 2 1 F ) reported on the pyrolysis of asphaltenes with analysis of volatile products for aromatization and condensation including elemental analyses and IR spectrometry. Petroleum and coal tar pitches were studied under the conditions of liquid phase pyrolysis to establish the mesomorphic products resulting for comparative purposes by Huettinger (46F).Magaril and Svintitskikh (65F) studied the thermal decomposition of asphaltenes which indicated that propane, ethane, and methane predominate in the gaseous hydrocarbons with the oils being naphthenic-paraffinic with short alkyl change in an is0 structure. Poxon and Wright (80F) also studied the characterization of bitumens by pyrolysis using gas chromatography. Saturated solutions in carbon tetrachloride were pyrolized on a hot wire using nitrogen as a carrier gas. Asphalt Rheology. Nakajima and Kamijima (68F) studied the viscosity temperature equations for paving asphalts over a temperature range of 5 to 200 OC using a sliding plate viscometer and a rotating coaxial viscometer. Various temperature functions were used as abscissas to give several plots in straight lines although not continuous over the whole range. Corbett and Schweyer (22F) presented a comprehensive summary of viscosity data for asphalts a t 60 and 135 "C on 84 different asphalts. Schweyer et al. (95F) presented data for viscosity of asphalts at 60 "C but showed that the results depend upon the apparatus and geometry used. I t was demonstrated further that pressure effects can cause a difference in result depending upon the flow mode used. This work was amplified by Schweyer and Lodge (94F) for studies of viscosity measurements a t temperatures from 10 to 60 "C. I t was demonstrated that pressure has a definite effect in increasing the viscosity of asphalts under the conditions studied. Reerink (83F) reported on the rheological properties of nonassociated asphalt solutions and suggested that association was the cause of the non-Newtonian behavior for concentrated asphaltene solutions. Schweyer in two papers (9ZF, 92F) presented methods demonstrating the use of a simple viscometer for routine testing a t temperatures below 25 "C down to approximately 10 "C. Studies of the low temperature behavior of asphalts are appearing to be of greater interest, and viscosity measurements in this region require special consideration because of the hardness of the asphalt. Savu et al. ( 8 8 F ) have reported on the use of differential calorimetry for determination of glass transition of asphalt and Schweyer (93F) has reported on the effect of pressure upon the glass transition temperature of asphalts. Horio et al. (4527) reported on low temperature measurements on 23 asphalts. Studies of the malthene viscosities as related to the asphaltene content a t these low temperatures is shown to be related to the low temperature properties. The use of dynamic methods fob measuring the viscoelastic properties of asphalts a t low temperatures has been presented by several investigators. Vater (105F) has studied the shear between two concentric 182R
cylinders and the effect of temperature ranges from 0 to 40 O F . Iijima (47F) reported on the dynamic viscoelasticity of catalytic blown asphalts and indicated that various polymers lowered the temperature susceptibility and their brittle point. Fritz (31F) reports on the measurement of the vibrational viscosity a t 25 to 125 "C. The tests were made on asphalts which are being used in test strips which are now under observation. Asphalt Paving. There are a very large number of publications appearing relating to the use of asphalt in highway pavement construction. Most of these articles are referenced through engineering publications and the engineering index and do not appear in the other science abstracts. There are three other major sources of such information that the interested researcher should consult for current developments. One is the Proceedings of the Association of Asphalt Paving Technologists which issues the results of papers presented a t their meetings approximately one year after the meeting which usually occurs in February. The second source is the activities of the Highway Research Board (to be called the Transportation Research Board in the future) which has an annual meeting in January and a midyear meeting in August with results of their papers and symposia being published in the Highway Research Record (will be known as the Transportation Research Record in the future). The third source of such information is also an operation of the Highway Research Board under the name of Highway Research Information Service ( H R I S ) which maintains a current record of ongoing research on bituminous materials. The science abstracts that have appeared during the past year on asphalts and paving are as follows. Ensley (29F) has reported on the possible interaction mechanism between asphalt-aggregate combinations in attempt to explain the stripping characteristics of asphalt. Barbour (7F) also has reported on similar interactions based on information from inverse gas liquid chromatography. Nitta (72F) discussed the various factors that effect the compaction of bituminous pavements including laboratory simulation methods. Arand (4F) surveyed analytical methods for asphalt content of pavements and considered the use of correction values for fillers. Kasahara (51F, 52F) discussed the effect of hot storage on asphalt deterioration of Kuwait and Wafra asphalts using gel chromatography and infrared analyses. Schmidt (90F) reported on the stability of asphalt paving mixtures as a function of the asphalt source, asphaltene content, viscosity, and filler types used. Cebrian ( 1 9 F ) reported on studies of the void content by several different methods as a function of the properties of the asphalt. Dempsey (27F) described a freeze-thaw apparatus for evaluating paving materials. Stahl (IOOF, 101F) studied the cohesion characteristics of asphalt and determined an equimodular temperature a t which the stiffness moduli of mixtures was equal for the same loading time. The author proposed an asphalt cohesion test using two strips of linen each coated with polyvinyl chloride with asphalt in between the two strips. Heukelom (44F) suggested a new improved method for characterizing asphaltic bitumen through the aid of their mechanical properties. De Bats (26F) proposed a computer program to determine the stiffness modulus based on Van der Poel's nomograph. Kasahara and Sugawara (50F) presented correlations between the properties of several asphalts, some with additives, and the catalytic blown asphalt, and the mechanical properties of mixtures made therefrom in wheel tracking and bending experiments. Miscellaneous Technology. Krenkler (57F, 58F) has presented information and correlation on the properties of
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5. APRIL 1975
asphalt made from mixtures of mideast and Venezuelan crudes. Broome and Wadelin (1317)and Nitsch (71F) have presented reviews on bitumens and asphalt. Stapel (102F) has discussed a specific test method for Trinidad asphalt in bituminous materials. Giavarini et al. (34F) has discussed the procedure for coating steel with oxidized asphalt. Busot and Schweyer (18F) discussed the thermodynamic response of asphalt under a dynamic compression technique. Traxler and Scrivener (104F) reported on a study of the hardening of asphalt when exposed to actinic light. I t was pointed out that the presence of trace metals seem to serve as catalysts in hardening the asphalts by actinic radiation. Lee and Huang (61F) studied the weathering of asphalts using infrared radiation and established a model for property change as a function of the weathering time. The hardening of asphalt is also studied by Imamura et al. (48F) using alumina gel chromatography and infrared spectra. The oxygen absorption was also studied. Pechenyi and Zhelezko (76F) studied the thermal relaxation effects of heating asphalts that had been stored for some time. Significant differences were noted for different asphalts as a result of the thermal treatment. Kurinov (61F) used infrared spectrometry to study the chemical and structural characteristics of bitumen exposed to salt solutions. Dubansky (28F) proposed an apparatus for determining the gases expelled from granitic and metamorphic rocks including those containing asphalt. Schamp and Van Wassenhove (89F) used thin layer chromatography for studying the separation of benzopyrene from bitumen. Savu et al. (87F) studied the use of differential calorimetry for paraffin. A rather interesting paper was presented by Oliver (73F) on the diffusion of oils into asphalts using tritium-labeled oils. This diffusion process is of considerable interest in the use of oils for rejuvenation of asphalt pavements. Nielsen (70F) reported measurements on the use of the Danish Ball Identation Test for asphalt mastics. Zenke (113F) gave a critical analysis of the ductility test and the need for strictly controlled test conditions. Costantinides and Schromek (24F) reported on the etching of air blown asphalts with diethyl ether to produce structural clearances on the surface. Gun et al. ( 4 1 F ) reported on the change in surface tension of 8 asphalts a t the air-asphalt interface under simulated conditions of air blowing. Certain petroleum coke items have also been included in this section since the transition from very hard brittle asphalts to coke is related to the amount of oil present. Allred ( 3 F ) reported on the use of X-ray diffraction peaks a t the 002 graphite line for determining the potential value in producing graphite. Prohaska and Hrmic (81F) discussed methods for analysis of petroleum cokes. Differences in different methods used in different countries were discussed. Filyushina and Zlotskii (30F) reported on the use of infrared spectrometry and adsorption for analysis of the raw materials that might be suitable as raw materials for petroleum coke manufacture. Sedov et al. (96F) discussed a device for determining the apparent density of petroleum coke.
Catalysts J. Free1 Gulf Research and Development Co., Pittsburgh, PA
Elemental Analysis. Bahr and Pauer ( 4 G ) determined metallic nickel in catalysts by dissolving in a 10% solution
of ferric chloride in hydrochloric acid, while adding carbon dioxide. The ferrous ion formed was titrated with ceric sulfate. Analysis time was 20 minutes and the mean error, f1.62%. Hulanicki et al. (40G) determined platinum by a similar technique. The catalyst was dissolved in aqua regia, treated with dilute cuprous chloride, and the resultant divalent platinum titrated biamperometrically with ceric sulfate. Abdurakhimova and Shamsiev ( 1 G )described a method for determining the metals in aluminum-copper-nickel catalysts after dissolution in nitric acid. The various finishes involved EDTA complexing and titration. An EDTA complexometric technique was also used by Levkovich (45G) to determine magnesium and aluminum in the presence of cobalt. A spectrophotometric method for platinum and palladium in zeolite catalysts was described by Basargin et al. (7G).Rhodazol-KhS was used as complexing agent and, of the many possible interferences tested, only gold, rhodium, and nitrate ion were problematic. Bocanegra Sierra et al. (13G) studied the spectrophotometric determination of palladium as a palladiazo complex, and examined the effects of 38 ions on the analysis. A spectrophotometric analysis for platinum and rhenium was reported by Wiele and Kuchenbecker (88G),who complexed rhenium with a-furildioxime. Tungsten and molybdenum interfered, but could be removed by preliminary extraction with benzoinoxime. Sokolov and Yampol'skii (80G) described a spectrophotometric determination of molybdenum in catalysts via a potassium rhodanide complex formed in acid medium. Analysis time was 1Y2 hours and the authors cite a mean error of f2.2%. Sat0 e t al. (74G)used X-ray fluorescence to determine molybdenum and cobalt in hydrodesulfurization catalysts. Interference from other matrix elements was negligible, and the results obtained were in good agreement with chemical analyses. Mohyuddin and Mohyuddin (52G) determined molybdenum in spent heavy oil catalysts by atomic adsorption spectrometry using a nitrous oxide-acetylene triflame. Equal amounts of 4% ammonium chloride and ethanol were used to suppress the effects of metallic and nonmetallic impurities. Berezovskaya et al. ( I I G ) determined the alumina content of faujasite-type zeolites by fusing with potassium carbonate and borax, dissolving in hydrochloric acid, and titrating with Trylon B. Silica did not interfere. The ratio of silica to alumina was then found from a plot of alumina content vs. silica/alumina ratio, which had been determined previously. Total time for the analysis was 1-11/2 hours. Sherman et al. (79G) described some limitations of the Karl Fischer method for water in catalysts. Comparison with infrared spectra and differential thermal analyses showed that the titration method yielded all the water adsorbed on boehemite, bayerite, and hydrargillite. In the case of y-alumina, only that water which desorbed with an activation energy below 15 kcal/mole was determined. Results for sodium and chromium zeolites were also reported. S u r f a c e Area Determination. Lowell and Karp (48G) discussed problems in measuring low surface areas by continuous flow methods and described a simple U-tube cell which eliminates anomalous peaks in such analyses. Scharf e t al. (75G) measured the surface areas of eleven industrial catalysts by a flow method which involved argon adsorption a t liquid nitrogen temperature followed by thermal desorption. They found good agreement with the static volumetric method. A gas chromatographic method studied by Buyanova et al. (18G) was also shown to give good agreement with conventional methods. N-Pentane was adsorbed a t 41 "C and chloroform a t 72 "C. Trubin (86G)described a flow technique in which the inlet concentration was varied
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exponentially. Isotherms determined from these measurements for butane on two silica gels and a silica-alumina were in good agreement with conventional measurements and were free of kinetic and longitudinal diffusion effects. Hydrogen was used as carrier gas, the measurements were made a t 0 "C, and surface areas could be measured with an error of f4%. Sharma and Fort (78G) used frontal, liquid-solid chromatography to measure adsorption isotherms for octadecane, stearic acid, and benzoic acid on graphite. Cyclohexane was used as carrier. The BET surface areas calculated from their data were internally consistent. A novel chromatographic approach to surface area determination was described by Ghosh et al. (32G).They found a relationship between surface area and the retention times for a series of n-paraffins, but the method works well only for adsorbents of similar pore geometry. Horiuti and Liu (39G) and Rudzinski e t al. (72G) described new methods for the calculation of monolayer capacities from adsorption isotherms. Both procedures gave values considerably higher than the BET method for microporous adsorbents. Specific Surface Area. The determination of metal particle size in supported catalysts was reviewed by Whyte (87G). He discussed chemisorption techniques, magnetic methods, electron microscopy, X-ray diffraction line broadening, and small angle X-ray scattering. Fruma (26G) discussed selective chemisorption as a means of measuring the dispersion of active components in catalysts. Topics included supported nickel, palladium and platinum catalysts, alkali promoted iron catalysts, and supported metal oxides. Aben et al. ( 2 G ) studied the temperature programmed desorption of hydrogen from platinum-alumina. Their data indicate a t least three types of adsorption site. Increasing the temperature of hydrogen pretreatment decreased the overall hydrogen uptake and changed the relative contributions of the three types of site. The gas titration method of measuring platinum dispersion on alumina was re-examined by Kanazirev et al. (42G). Each surface platinum atom retained one hydrogen atom after either hydrogen chemisorption or the titration of pre-adsorbed oxygen with hydrogen. The authors concluded that the ratio of adsorbed hydrogen to hydrogen consumed in the titration was always 3:l. The titration method was studied calorimetrically by Basset et al. (8G). Their results also supported a 3:l ratio provided the residual hydrogen pressure was below 0.1 mm Hg. Spindler and Kraft (82G) compared data obtained by hydrogen-oxygen titrations with X-ray diffraction line broadening measurements of some platinum-clay mineral catalysts. Good agreement was generally obtained. Menon et al. (50G) used hydrogen-oxygen titrations to measure platinum and rhenium dispersions separately in naphtha reforming catalysts. Oxygen chemisorption measured by a pulse method was believed to give the surface area of both metals. The sample was then treated with hydrogen a t 25 "C and a second oxygen chemisorption measurement used to determine the surface area of platinum alone, since oxygen initially chemisorbed on rhenium was not removed by hydrogen a t this temperature. Free1 (25G) reported similar titration data for this system but did not identify the contributions of the individual metals. Benson et al. (IOG) measured the dispersion of palladium on alumina by titrating preadsorbed oxygen with hydrogen or deuterium a t 100 "C. Results were in good agreement with values obtained by oxygen and carbon monoxide chemisorption and by X-ray diffraction line broadening. The authors caution that temperature and hydrogen pressure must be such that @-palladiumhydride does not form. 184R
Buyanova et al. (16G) also studied the measurement of palladium dispersion on alumina. They measured oxygen and carbon monoxide chemisorption on three palladium blacks of known surface area, and used the resulting adsorption stoichiometries to interpret uptakes on palladium-alumina. Oxygen was the preferred adsorbate. Carbon monoxide gave consistently higher values, which was ascribed to differences in the carbon monoxide species adsorbed on supported and unsupported palladium. Buyanova et al. (17G) used oxygen chemisorption to measure iron dispersion on alumina. Oxygen uptakes measured by the static and pulse adsorption methods were in good agreement, but a number of difficulties were encountered in measuring iron dispersion by this method. The use of oxygen and nitrous oxide chemisorption to measure free silver surface areas was reported by Scholten et al. (76G). Comparison with BET surface areas and X-ray line broadening measurements showed that either technique may be used on ethylene expoxidation catalysts. The limitations of each method were discussed. Porosity. Lippens (46G) reviewed the porous structure of catalysts. Topics included the origin of pores in catalysts, the calculation of pore size distributions from nitrogen adsorption-desorption isotherms and from mercury penetration data, and use of the t-plot method. Karp et al. (43G) described a new flow method for measuring pore volume which permits rapid scanning of the hysteresis loop and requires no void volume corrections. Romotowski and Polanski (69G) determined pore volumes by measuring changes in the electrical impedance of catalysts as the pores were filled with water. Hanna et al. (33G) measured oxygen adsorption isotherms on several silica gels a t 77.3 and 90 K. Analysis of the t-plots calculated from such isotherms gave pore volume distributions equivalent to those obtained from nitrogen adsorption isotherms. Mueller (5%) discussed a model based on potential theory which described the adsorption behavior of a heterogeneous surface consisting of mesopores and micropores. He used this new approach to calculate the micropore volume of activated carbon from adsorption isotherms. Delon (20G) also reported a new approach for calculating pore size distributions from adsorption isotherms, as did Radjy and Sellevold (68G) whose method interprets t-plots somewhat differently in the micropore range. Rootare (70G) reviewed the determination of pore size distributions by mercury porosimetry and discussed factors affecting the accuracy of the method and its use for measuring particle size, surface area, and contact angle. Calculations of pore size and shape from porosimetric hysteresis curves were discussed by Svata (82G) and Rootare and Spencer ( 7 1 6 ) developed a computer program for the calculation of pore volume and pore area distributions from porosimetry data. Wotzak (89G) reported calculation procedures for correcting errors due to limited pore accessibility in mercury penetration experiments, while Krasotkin et al. ( 4 4 3 ) studied the effect of particle size on unfilled volume and defined a particle size above which the volume unfilled with mercury may be ignored. Diffusion Measurements. MacDonald and Habgood (4%) described a gas chromatographic technique for measuring mass transfer resistances in zeolite catalysts. Benzene, octane, and decane pulses were passed through fresh and coked sodium X zeolite using either hydrogen or nitrogen as carrier gas. The Giddings-Schettler approach was used to distinguish between gas phase and micropore diffusion. Experimental requirements were stringent. Hashimoto and Smith (34G) used a pulse chromatographic method
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to measure the diffusion rates of nitrogen and n-butane in the macropores of commercial pellets containing 5A zeolite and 20 wt% clay binder. The moments of the effluent peaks were interpreted according to a bidisperse pore theory which assumed adsorption in the zeolite micropores and no adsorption in the macropores. Macropore tortuosity factors of 3-4 were calculated in this manner. The same authors (35G) used a chromatographic method to measure both macropore and micropore diffusivities in alumina pellets. Their technique was rapid and simple and gave diffusivities within 25% of the true values under proper operating conditions. Haynes and Sarma (36G) described a new method of calculating diffusivities from gas chromatographic data when the catalyst has a bimodal pore size distribution. It takes account of effective micro- and macropore diffusivities in such systems and explains the anomalously high diffusivity values sometimes reported for samples of this type. Midoux and Charpentier (51G) reported measurements of diffusivity in liquid filled pores. Naphthalene, styrene, p-xylene, and ethylbenzene were used as liquid tracers and monitored with a differential ultraviolet spectrophotometer. Tortuosity factors of 2.8-3.0 were measured for a hydrodesulfurization catalyst in the form of 3-mm diameter spheres. Omata and Brown (62G) calculated diffusivities for three catalyst samples by the Johnson-Stewart method and compared predicted with observed flux as a function of temperature and pressure. Predicted diffusion rates were confirmed for Harshaw alumina, but predicted and observed diffusion rates did not agree for pelleted Aerosil or for a ferric oxide gel. In a second publication, the authors (63G) showed that diffusion rates predicted by the dusty gas equation differed from experimental values in pores less than 50-A radius. Hegedus and Petersen (38G) described an improved single-pellet reactor for simultaneous measurements of reaction rate and mass transfer effects. Reactant and product concentrations were measured a t the center plane of a flat catalyst slab by quantitative infrared spectrometry. Application to the hydrogenolysis of cyclopropane to propane in hydrogen gave values of the effective diffusivity, effectiveness factor, 'rhiele parameter, and kinetic rate constant. The same authors (37G) reported a modified method for determining the mechanism and kinetics of catalyst poisoning in a single pellet reactor. Measurements were made in the diffusion influenced region where the poisoning reac: tion has a large effect on the center plane concentration. In an interesting study, Morariu and Mills (53G) used pulsed gradient, spin echo NMR to measure self diffusion in water adsorbed on silica. Surface attraction ceased to influence diffusional mobility at about 3-4 monolayers, but the self diffusion coefficient reached that of bulk water only above 15 monolayers. Surface Acidity. Methods used to measure surface acidity were reviewed by Forni (24G), who discussed the adsorption of gaseous bases, titration techniques, calorimetry, infrared spectrometry, and the use of special test reactions and poisoning procedures. Benesi (9C) compared pyridine and 2,6-dimethyl pyridine adsorption on alumina, silica-alumina, and silica gel. He concluded that the substituted pyridine adsorbs preferentially to protonic acid sites a t 400 "C due to steric effects. Peri (65'2) utilized infrared and a potentiometric titration method to study acid sites on ultra-stable faujasites. Two groups of sites were revealed by each method, one of which was virtually eliminated by treatment with acetylacetone. Topchieva and Thuong (85G) used ammonia adsorption and Hammett indicators to measure the acidity of various
zeolites, The techniques gave comparable results, but it was concluded that the strength distribution of strong acid centers was given best by ammonia chemisorption a t 350450 OC. Navalikhina et al. (59G) compared heats of adsorption for benzene, ammonia desorption, and pyridine poisoning of cumene cracking in a study of acid sites on decationized Y zeolite. They concluded that cumene cracking was catalyzed by strong acid sites. The infrared spectra of several amines adsorbed on X and Y zeolite were reported by Jacobs et al. (41G). Partially ammonium exchanged sodium zeolites were deamminated and the adsorption of mono-, di-, and triethylamine, isopropylamine, butylamine, and pyridine studied by quantitative infrared spectrometry. Adsorption was shown to occur by reaction with acidic hydroxyls, by coordination with residual sodium ions, and by interaction with dehydroxylated sites. Szczepanska and Malinowski (83G) measured the acidic and basic centers on the surface of sodium modified silica. Carbon dioxide chemisorption was used as a probe for basic sites, ammonia adsorption as a probe for acidic sites. Ballivet et al. (6G) studied the poisoning of active sites for cis2-butene isomerization on silica-alumina. Techniques were devised for the selective poisoning of oxidizing, reducing, and Lewis and protonic acid sites. The authors concluded that two simultaneous deactivation processes occur, one on a Lewis acid and one on a Bronsted acid center. General. Phillips and McIlwrick (67G) described an application of sample vacancy chromatography to studies of catalytic reactions. They studied the hydrogenation of hept-1-ene over rhodium. Berg and Sokolova (12G) determined the cracking, isomerization, and hydrogenation activities of a hydrocracking catalyst in a single experiment using isooctane. Cracking activity was measured by isooctane conversion; hydrogenation and isomerization activities were inferred from the distribution of C4 products. An unusual approach to the evaluation of chromia-alumina catalysts was reported by Naberezhnova et al. (57G). They compared butane dehydrogenation and propylene hydrogenation over the same catalysts and concluded that initial activity for propylene hydrogenation was the best indicator of average activity for prolonged butane dehydrogenation. A laboratory method for measuring the activity of cracking catalysts was given by Petrykowska et al. (66G).The procedure utilized the fixed bed approach and was operated in 6-10 cycles, each including cracking, purging, and regeneration. Emmett (22G) reviewed the use of isotopic tracers in catalytic studies. Tracer studies of adsorption, catalytic mechanisms, and the participation of lattice ions in catalysis were among the topics covered. Burwell ( 1 9 G ) reviewed the use of deuterium in catalytic studies. Topics included the use of deuterium labeled molecules to study reaction mechanisms and to determine the rate limiting step in a catalytic reaction. The use of various spectroscopic techniques to analyze tracer experiments was also discussed. Morris and Tinker (54G) developed a special cell which allowed the infrared and ultraviolet-visible spectra of reacting solutions to be recorded at high temperatures and pressures. They studied the hydroformylation of olefins with a rhodium catalyst in this way and discussed possible reaction mechanisms. A pulse chromatographic method for studying adsorption-desorption kinetics during a catalytic reaction was devised by Yanovskii and Berman (90G).The technique was based on an analysis of retention times and shapes of the reactant and product peaks at the reactor outlet. Gerritse and Huber (31G) reported a chromatographic method for studying the co-adsorption of gases on cata-
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lysts. They compared chromatograms of binary gas mixtures equilibrated over catalyst with those for identical mixtures not exposed to catalyst. Binary mixtures of water, methanol, ethanol, acetone, benzene, hexane, and pentane were investigated. Silica, chromosorb W, and glass beads were the solids employed. The use of ternary phase diagrams in the study of co-adsorption phenomena was reported by Eden and Ashboren (21G). Monolayer capacity of each adsorbate was represented by a fixed point in the ternary phase diagram on the assumption that solid and adsorbate could be treated as a single phase. Methods for determining the coordinates and composition of this point were devised. Geisenheimer et al. (30G)used a thermal desorption method to investigate the co-adsorption of gases on a single grain of catalyst and used the technique to study the co-adsorption of water and carbon dioxide on 13X zeolite. Timofeev et al. (84G) measured the adsorption of organo-sulfur compounds on A and X zeolites by a chromatographic technique. The method predicted the relative efficiencies of various zeolites for removing organosulfur impurities from hydrocarbon streams in about 10 minutes with a claimed precision of 2.5%. Mukherjee et al. (56G) described an accelerated aging test to measure the dusting characteristics of naphtha reforming catalysts which correlated well with plant experience. Catalyst screening by differential thermal analysis was reported by Papadatos and Shelstad ( 6 4 G ) who were able to correlate the relative activities of ten mixed oxides for toluene oxidation with the temperature rise observed by DTA. Borthakur et al. (14G) used simultaneous DTA and TGA to study impurity concentrations in commercial zeolites, while Schubert and Barth (77G) designed a measuring head for DTA in which gas flows directly through the sample, but does not contact the thermocouples. Buechler and Turkevich ( 1 5 G ) reported the Raman spectra of silica gel, Vycor glass, molybdenum and uranium trioxides on Vycor, platinum on Vycor and europium Y zeolite. Water on silica was found to have the same Raman spectrum as bulk water. Gallei (27G) reviewed the application of attenuated total reflectance spectrometry to surface chemistry. He discussed theory, the selection of suitable reflection elements, comparisons with infrared transmission spectrometry, and use in the study of adsorbed layers and catalyst surfaces. Ryason (73G) described a new infrared cell, useful for transmission studies on catalysts in gaseous systems, and Liu e t al. ( 4 7 G ) studied the infrared spectra of hydrogen sulfide and carbon disulfide on y-alumina. Bakulin et al. (5G) used infrared and ultraviolet spectrometry to characterize coke deposits on a platinum-alumina reforming catalyst. The spectra obtained were characteristic of unsaturated C5 ring derivatives and coke formation via a diene synthesis mechanism was postulated. Gardner and Casey (28G) reviewed the application of electron spin resonance spectrometry to catalysis studies. Topics included the identification of active sites on chromia-alumina and copper exchanged zeolites, the detection of free radical intermediates on catalyst surfaces, and studies of electrocatalytic processes. Asmolov and Krylov ( 3 C ) correlated electron spin resonance and diffuse reflectance spectra in a study of the reduction of molybdena-alumina and molybdena-magnesia. They studied oxidation states and environments of the molybdenum and found that more coordination and valence states were for-d with increasing molybdenum content. An electron spin resonance study of cation radical formation on the surface of molybdenum-alumina and molybdenum-silica was reported by Naccache et al. (58G). Perylene, anthracene, l86R
benzidene, and 1,l-diphenylethylene each formed the corresponding cations, probably by adsorption on Lewis acid sites with subsequent transfer of an electron to hexavalent molybdenum. Gay (29G)used carbon-13 nuclear magnetic resonance to study carbon dioxide, ethylene, acetone, toluene, and other molecules adsorbed on silica. Chemical shifts were readily observed upon adsorption. The use of secondary ion mass spectrometry for the characterization of surface monolayers was discussed by Evans (23G). Studies of hydrocarbons and their ions on various surfaces were cited. Ogilvie and Wolberg (61G) studied internal standards for use in calibrating photoelectron spectra of supported catalysts. Measurements on a series of zinc-oxide/alumina catalysts showed that the aluminum 2p electron was a more reliable internal standard than the residual carbon Is electron.
Physical Properties N. W. Lambert Union Oil Co. of Calif., Research Dept., &ea, CA
Rheology appears to have occupied a position of major interest among investigators during 1974. Considerable interest was also evident in the development and use of mathematical models for predicting volatility, molecular weight, pour point, and other physical properties. In terms of total activity as measured by the number of papers included in the review, an upward trend over recent prior years is apparent. Rheology. The importance of viscosity in automotive lubrication, and the field criteria for developing new tests were well established by a series of papers on cold flow mechanism of crankcase oils. Selby ( 8 2 H ) discussed in detail the test requirements, including some pitfalls that can occur in developing new tests, and the need to keep test methods abreast of field requirements. Tao and Waddey (90H) used various viscometers and a cold pumping simulator to show that pumping performance in cold engines is primarily controlled by the non-Newtonian viscosity of the suggested that a vacuchilled oil. Stewart and Smith (88H) um pipet rig gave more consistent results a t borderline pumping temperatures than did the Brookfield viscometer, and that results obtained with a Haake Rotovis viscometer gave a reasonable correlation with a pumpability simulator. Nolf ( 6 3 H ) reported general agreement between Brookfield viscosities and results obtained utilizing a pumping rig similar to that in a 230 CID, L-6 engine. McMillan and Murphy ( 5 4 H ) also used Brookfield viscometry to conclude that an oil with a viscosity near 1000 poises will cavitate if it exhibits a yield stress, or if the low-shearhigh-shear viscosity ratio is greater than 2:1. Tuzar et al. (92H) used extrapolated viscosities at 0 O F to compare with dynamic viscosities measured with the SAE cold cranking simulator,
ccs-2.
Various new apparatus for determining viscosity were reported. Wolf (IOOH) described apparatus and procedure in which the time required to pump 200-ml samples at f 5 "C to -45 OC and 0.6-0.8 atmospheres correlated with viscosity. Drenchev ( 1 7 H ) described an improved capillary viscometer for measuring dynamic viscosity, and Priel et al. ( 7 1 H ) described a method for determining the time of flow in a capillary viscometer with an absolute accuracy of 3 ppm. Preston and Hubbard (70H)reported on a Bourdon-2 viscometer for direct and continuous measurement of liq-
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
uid viscosity over the range of about 20-1000 cP. A high pressure capillary rheometer of new design was reported by Kemblowski and Kiljanski (38H) for studying the rheological properties of polymers, greases, muds, and other highly viscous fluids. A rotational, double co-axial cylinder viscometer which directly measures viscosity and yield stress without need of a correction was described by Enoksson (21H).Larionov et al. ( 4 8 H ) reported on an automatic viscometer with a freely floating cylinder using a photoelectric pulse counter, and Winer (99H)described the development of a viscometer for high pressure use in which viscosities a t 100 and 210 O F were determined on a paraffinic oil a t 50,000 psi, on a leaded gasoline, and on a 50/50 mixture of the oil and gasoline a t 80,000 psi. Various papers concerning the viscosity of pure compounds appeared in the literature. Rastorguev et al. ( 7 4 H ) determined the viscosities of n-Cl3H28, n-CldH30, and n C16H34 a t 250 "C using an experimental high pressure apparatus. Experimental data reportedly differed by 1.7% from the calculated values. The viscosity and thermal conductivity of propane vapors and liquid were presented by Bonscher et al. ( 7 H ) as functions of temperatures from -300 to +lo00 O F and a t pressures up to about 10,000 psia. they presented similar data on In a subsequent paper (8H) propylene. Ford and Singleterry (25H) plotted the kinematic fluidity of 20 n-alkanes vs. the square of the absolute temperature and proposed a simple equation for use as an interpolation formula for organic liquids in the low viscosity region. The equation constants of the C1-C20 alkanes were reported by Hesselbarth ( 3 1 H ) for use in Girifalco's equation for calculating the temperature-dependency of viscosity of pure liquid hydrocarbons. An empirical formula was presented by Mamedor and Tairov (57H) for calculating the viscosity-temperature constant for c5-c16 n-alkanes. Naziev et al. (60H) derived empirical formulas for the viscosity of gaseous paraffins and olefins a t elevated pressures and various temperatures. Klose and Toufar (40H) reported on the viscosities of five hypothetical gas mixtures. Naziev e t al. (60H)developed empirical formulas for comparative calculation methods of correlating data on dynamic viscosity of hydrocarbons, and Marmin and Sommelet (59H)presented general formulas for precise calculation of the VI of lubricating oils. A nomograph for determining the kinematic viscosity of a binary blend of oil was proposed by Zanker (106H). Mannheimer (58H) presented equations for shear stress, shear rate, and meniscus velocity for the calculation of viscosity from immiscible displacement of highly viscous materials in capillary tubes. Weber (97H) presented a review of the fundamentals of viscosity covering principles and units with a discussion of various capillary and rotary viscometers currently available. Rafikov et al. (72H) reaffirmed the effects of thermal history on the viscosity of crude oils and described the significant part which resinous-asphaltic materials in the crude have on dynamic viscosity. Various possible mechanisms for these effects were discussed. Rheological behavior of shear degradable crude oils a t temperatures below or slightly above their pour points was discussed in detail by Petrellis and Flumerfelt (67H). Groode (28H)presented equations for the flow of real, plastic, and pseudoplastic fluids, and the effects of paraffin wax, asphaltenes, and emulsions on the flow of crude oil. Denis and Parc (13H) discussed methods of estimating the limiting viscosity of components with a designated pour point. Duggins ( 1 8 H ) assessed the effect which yield stress has on the pumping requirements of crude oils, both in the initiation of flow from rest and in the ultimate steady state condition. Paul and Cameron (66H)described
a procedure for absolute high pressure micro-viscometry based on refractive index. Letsou and Stiel ( 5 1 H ) studied the viscosity of saturated non-polar liquids a t elevated temperatures. Distillation and Volatility. A comprehensive discussion of the developments in the field of distillation between 1940 and 1973 has been arranged by Zuiderweg ( l I l H ) ,including the significance of computers and gas-liquid chromatography in distillation. Advances in distillation equipment, particularly concerning new types of packing and new methods of controlling columns are discussed. A short path rotating evaporator was described by Kolobielski (42H) which allows recovery without alterations of the nonvolatile components of gasoline, distillates, and fuel oils. Packer et al. (65H)describe a 40 cm3 recycling vapor liquid equilibrium still with direct injection of the vapor into the carrier stream of a chromatographic analyzer unit. Skorokhod et al. (84H) reaffirmed the precision of the EdmisterPallock method of plotting the true boiling point curve for a petroleum fraction. Hickerson (32H) reported that results by ASTM D2892 (15-theoretical plate column) were in reasonably good agreement with results by D2887 (simulated distillation by gas chromatography) for samples with wide boiling ranges. Samples with narrow ranges were sensitive to gas chromatographic conditions. In a similar investigation by McTaggart et al. (55H) using four Middle East crude oils, three modifications of ASTM D2887 were tested for correlation with ASTM D2892. A multiple linear regression analysis was used by Ford et al. (24H) to study the correlation of simulated distillation by gas chromatography (D2887) with ASTM D86 and D1160 data. Rawat et al. (76H) used infinite dilution activity coefficients and partion coefficients of butadiene and four isomeric butenes in six solvents to calculate the relative volatility of the olefins in order to find the most suitable solvent for the extractive distillation of butadiene. Weiner and Parcher (98H)used factor analysis of retention indices to predict the carbon number, heat of vaporization, molecular weight, molar refraction, van der Waals constants, and boiling points of esters and alcohols. Mathematical models were described by de Bruine and Ellison ( 1 0 H ) by which the Reid vapor pressure and distillation properties of a gasoline can be predicted. Gouw (27H) describes a simplified graphical technique which gives an average standard deviation considerably smaller than the deviation derived by ASTM D2887, simulated distillation method. A formula was given by Luskin and Morris ( 5 2 H ) for predicting the Reid vapor pressure from gas chromatographic data and the activity coefficients published by API. King (39H)proposed a method for correlating and extending vapor pressure data to lower temperatures using thermal data. Laurance and Swift (49H) combined experimental and literature values to calculate relative volatility for a propanepropene system from -20 to $160 O F . Carruth and Kobayashi ( I I H ) determined the vapor pressure of normal paraffins, ethane through decane, from their triple points to about 10 mm Hg, and Ermolaev et al. (22H) used a differential tensimeter to determine the saturated vapor pressure of lubricating oils a t 20-200 "C. The explosive limits, flash point, fire point, and auto ignition properties of various hydrocarbon fuels were presented by Weber (96H). Methods of determination were also included. Flammability properties of hydrocarbon solution in air were calculated by Affens and McLaren ( I H ) . Lower and upper flammability limits, heat of combustion, flash point, and explosiveness were included. Derived equations demonstrate that the vapor pressure of individual constituents plays a more important role than the concen-
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tration in the overall flammability properties of a liquid. Walsham (94H) utilized a computer method to predict the TOC flash point of a mixture, and Gerstein (26H) derived an expression for predicting flammability limits. The auto ignition temperature of 44 pure hydrocarbons and various binary mixtures were reported by Raseev and Barbatu (73H). Molecular Weight. A review was given by Bode ( 6 H )on the methods of molecular weight determination. Holle et al. (33H) described an apparatus used to monitor molecular weight changes in motor gasoline and vacuum distillate streams during hydrocracking. The same authors (34H) compared vapor osmometry with the cryoscopic method and discussed the advantages and disadvantages of osmometry. Lakatos and Lakatos (46H) determined the molecular weight of CS-Cl; paraffins in benzene by vapor pressure osmometry. In a separate article by Lakatos (47H), a method was elaborated for the determination of the average molecular weight of Hungarian oils and fractions by osmometry in which the interference of volatile components was eliminated. An apparatus for the continuous determination of molecular weight was described by Woodle ( 101H). Various relationships for calculating molecular weights have been proposed. Kurganov e t al. (44H) proposed an empirical method for calculating the molecular weight as a function of the average boiling point, density, and refractive index. Andriasov ( 2 H ) reported formulas for calculating molecular weight of petroleum fractions based on density, and resin, asphaltene, and sulfur contents. A similar paper by Andriasov ( 3 H ) suggests treating the petroleum as a two-component system of hydrocarbon and resin-asphaltic substances, and a formula is presented for calculating molecular weight on that basis. Formulas for calculating molecular weights of C2-Cl6 paraffins, C I S + paraffins, paraffinic petroleum, and complex petroleum fractions were also presented by Andriasov ( 4 H ) . Vitenberg et al. (93H) discussed the precision of the gas chromatographic molecular weight determination with a density detector. Density, Refractive Index, and Surface Tension. Zanker (110H) described a nomogram for calculating the density of liquified petroleum gas. For 45 LPG’s tested, the average difference between the calculated and the determined densities was 0.09 gram per liter. Kurganov et al. (45H) discussed the relationship between density and refractive index of petroleum fractions. Spencer and Danner ( 8 5 H ) used extensions of the modified Rackett equation to predict the bubble point density of mixtures, and Rea et al. (77H) used the Rackett equation in conjunction with the Yen-Woods and Chueh-Prausnitz correlations to predict the effect of pressure and temperature on the liquid densities of pure hydrocarbons. Sedov et al. ( 8 1 H ) described an apparatus for determining the apparent densities of petroleum coke. Oklahoma State University presented a computer program for calculating the liquid density of any hydrocarbon mixture of known composition. The program is written in FORTRAK IV (113H). Empirical relationships were reported by Watanabe and Moroto (95H) between refractive index and boiling point for a series of pure alkanes, alkenes, n-alcohols, alkyl chlorides, and aromatic hydrocarbon. Empirical formulas were presented by Eisen et al. ( 2 0 H ) for relationships between densities and refractive indices of positional and configurational isomers of n-alkenes. Besserer and Robinson ( 5 H ) used refractive indices of ethane and carbon dioxide to calculate their compressibility factors. An optical method utilizing the angle of reflection of a laser beam was used by Roedel et al. (78H) to determine 188R
surface tension. LeGrand and Gaines ( 5 0 H )used published data on a homologous series of liquids to judge the general validity of an equation expressing surface or interfacial tension as a linear function of molecular weight. Jewulski (37H) reported the measurement of surface tension over a range of 30-70 O C for crude oils with respect to air, distilled water, and solutions of surfactant. Pour and Freezing Points. A convenient method of predicting the pour point of wide boiling (>60 O F ) petroleum fractions was suggested by Nelson (62H),in which the pour point when plotted vs. the 65% TBP temperature, constitutes a substantially smooth curve. Ostashov et al. (64H) presented a mathematical expression of the dependence of the pour point of diesel fuels on the pour point and weight ratios of the initial components. Using the suggested formula, the pour point of any binary mixture can be estimated. An apparatus and method for determining the purity of a liquid by measuring its freezing point was described by Huber et al. (35H),and Zanker (109H) presented a nomogram for calculating the purity of hydrocarbons from their freezing point. Simpson (83H) developed an apparatus for the automatic and rapid determination of freezing points of hydrocarbon mixtures, e.g., gasoline, fuel oil, etc., with an accuracy equivalent to the ASTM method. Thermal and Miscellaneous Other Properties. Thermal conductivity of various pure organic compounds and petroleum fractions were measured in a comparative type transient hot wire apparatus a t 20-120 O C by Mallan et al. (56H).Rastorguev and Bogatov ( 7 5 H ) measured the thermal conductivity of n- heptadecane and n-octadecane a t high pressures and temperatures, and an equation was derived to correlate thermal conductivity with pressure. Efendiev (19H) proposed a formula for calculating thermal conductivity of lubricating oils within a wide temperature range from the conductivity a t 253 K, the critical temperature and pour point. Tatevosov (91H) used the stationary heated-filament method to measure thermal conductivity of various synthetic refrigeration oils and discussed the effect of oil additives on the data. Yazima (104H), using water as a standard, evaluated the cooling ability of oil by measuring the temperature change of a wire before and after a current passed through it. A method for determining the isothermal compressibility of liquids was described by Downer and Gardiner (14H). Isothermal compressibilities of seven crude oils were subsequently determined (15H). A detailed evaluation of methods for the prediction of various critical properties of hydrocarbons was made by Spencer and Daubert (86H). Heats of formation in hydrocarbon mixtures was estimated by a system described by McCarthy and Smith (53H). Spencer and Daubert (87H)reported the Li method is best for predicting critical temperatures while a procedure of Kreglurski et al. is most accurate for predicting critical pressure. A simple approximation formula for calculating the compressibility factors of commercial gas mixtures was reported by Herning ( 3 0 H ) , and Jaeger (36H) presented equations for predetermining the density, vapor pressure, and viscosity as a function of the temperature and composition for oil-refrigerant mixtures. Kohoutek and Odstrcih (41H) described a computer program in ALGOL for calculation of equilibrium evaporation curves and for equilibrium states at determined temperatures and pressures. A FORTRAX IV program developed by PVT Inc. of Houston can be used to predict thermodynamic and physical properties of natural gas and condensate (112H). Equations and graphical representations were derived by Roth and Laux (7” for the separate relationship of molecular weights, carbon:hydrogen ratios, and density to a material type
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
coefficient that expresses the structure of the hydrocarbon. Wuensch and Hoffman (102H) reported that the enthalpy changes measured on heating naphtha fractions, a crude oil, and a diesel oil were in good accord with the values calculated when using “pole materials.” Pole materials are defined as groups of model substances for which plots of the logarithm of the vapor pressure vs. the reciprocal of an empirical temperature function are straight lines that intersect in a “pole” in the super critical region. Povarnin and Kurbanbendyev (69H) calculated the thermophysical properties of crude oil and petroleum products by thermodynamic similarity methods. A method for calculating mutual solubilities of paraffinic and aromatic hydrocarbons and water a t 0 and 25 “C was developed by Polak and Lu (68H).Such data are of interest in oil spills. Hayduk and Castaneda (29H) discussed the solubility of propane and butane in normal paraffin and in polar solvents. A method for measuring solubility of gases in liquid petroleum products was described by Krzyzanowski and Wislicki ( 4 3 H ) , and Esposito (23H) described a method involving thin layer chromatography for evaluating the solvency properties of hydrocarbons used as solvents for organic coatings. Yamada and Gunn (103H) slightly modified the generalized Rackett equation for predicting liquid volumes and improved its predictive accuracy by about an order of magnitude. A nomogram was presented by Zanker (105H) for determining additive properties of a binary mixture, and a second (107H) for converting weight percent to volume percent and vice versa in binary systems. A third nomogram by Zanker (108H) is applicable to the calculation of liquid volumes in cylindrical and spherical tanks when the liquid level and the tank dimensions are known. Three rather specialized papers were included in the literature-one by Sucker (89H) which described an analytical method for measuring the tack of Vaseline; a second by Schmidt and Sucker ( 8 0 H ) describing the influence of physical and chemical data on the use properties of petrolatum; and, third, a procedure described by Bormann and Deutsch ( 9 H ) for determining polyesters such as polyhexadecymethacrylate in paraffinic substrates by NMR. Downer and Inkley (16H)reported that the thermal expansion of all crude oils examined was about 8% more than the ASTM-IP petroleum measurement tables predicted.
Hydrocarbons M. P. T. Bradley The Standard Oil Co.(Ohio)
As in past years, gas chromatography holds sway as the most popular analytical technique for the analysis of hydrocarbons. A large number of applications are reported, both new and modified, using new column materials or more precise measurement. A substantial number of authors show a preference for using capillary GC methods. One GC topic for which a distinct preference is shown in Europe is the use of Retention Indices for the identification of compounds. A renewed interest in Mass Spectrometry, both as a single technique and also combined with gas chromatography, is evident. Research into the use of NMR and GCIIR applications seems to have slowed somewhat. The trend in hydrocarbon analysis shows a strong interest in the polycyclic compounds for which many applications of liquid chromatography and sophisticated separa-
tion techniques are reported. The second major interest area is in the analysis of hydrocarbons in the environment. The major techniques used in this important area are Gas Chromatography and Infrared Spectrometry. Environmental Applications. The identification of oil products and oil spills in the environment, particularly in water, has been a topic of some interest, with both specific techniques reported and also review articles. Adlard et al. (71) reported in a review article with 37 references that IR spectroscopy, emission spectroscopy, gas chromatography and thin layer chromatography are the most likely to be generally available. A standard gas chromatography method for pollutant identification developed by the Institute of Petroleum is also reported. A second review article by Jeltes et al. (1701) concentrates on the problems of oil pollution. The use of gas chromatography for oil in water and infrared spectroscopy for the determination of oil in soils and sediment is discussed. Adlard and his coworkers reported on the use of the flame photometric detector as an aid to oil spill identification (51, 61). Ehrhardt et al. reported a gas chromatographic technique for identifying oil spills in a marine environment (911);they report that distinguishing features are still present in crude oil spills after 8 months’ weathering. A similar chromatographic method together with a method of correlating potential spill sources to actual spills was reported by Zafiriou and his coworkers (3881).Zafiriou later reported an improved method (3891). Garza and Muth (1151) reported a technique using simultaneous flame photometric and flame ionization detection of the chromatogram. Kawahara (1801)used both gas chromatography and infrared spectroscopy for the characterization and identification of spilled residual fuel oils in surface waters. The oily material was initially collected by surface skimming and dichloromethane extraction. The use of infrared techniques was investigated by Mattson (2441) who studied 40 samples of petroleum oil by infrared spectroscopy and concluded that there existed sufficient differences between the “fingerprints” of the various oils for them to be usable for identification. Jeltes ( I 711) compared infrared with gas chromatography for the determination of mineral oil in water. His conclusion was that gas chromatography was the most satisfactory technique for the qualitative and quantitative analysis of CC14 extracts. Infrared showed the presence of dissolved polar compounds in addition to the mineral oil. A similar extraction technique with an infrared finish was used by Hellmann et al. (1421) for the determination of alkanes in water. A very sensitive technique for measuring hydrocarbons in water was reported by Novak et al. (2641). This technique is limited to simple hydrocarbons with a boiling point less than 140 “C. The hydrocarbons were removed from the water by stripping with an inert gas. After separation on a 5-m X 2.5-mm glass column packed with 10% Carbowax 20M on Chromosorb W AW; the column effluent was fed to a GCIMS separator. Compounds a t concentrain water could be determined in the tions of 0.1 X mass spectrometer. Eggertsten and Stross (891) used a heated platinum boat to determine volatile hydrocarbons in water by heating the sample in nitrogen for 5 minutes a t 150 “C. The temperature was then raised from 150 to 550 “C for 5 minutes in order to determine non-volatile organic carbon. The sensitivity is reported to be 0.2 ppm for hydrocarbons. Levy et al. (2081) also used a boat inlet, although, in their case, the purpose was to avoid contaminating the column by residues when fingerprinting crude oils, residual fuel oils, or their weathered residues. The weighed sample contained in an aluminum boat is placed in the inlet a t 390 “C for 5 min-
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Utes and then removed. The column is then programmed a t 6 OC/minute from room temperature to 400 OC. A technique for examining underground waters for the presence of oil or gas condensate contamination was reported by Mel'kanovitskaya (2461). In this procedure, the water samples are extracted with nitrobenzene and the extracts examined by gas chromatography for benzene, toluene, and xylenes. Concentrations of as low as 0.01 mg/l. were readily determined. Levy (2071) reported a UV method for comparing the hexane extract of water with known materials. By measuring the absorption a t 256 nm and 228 nm, the ratio of which is independent of concentration, residual oils and lubricating oils could be distinguished from each other. A procedure reported by Whitmer et al. (3801) is particularly applicable to the problem of oil in ships ballast water. In this procedure, the light transmission of an ultrasonically emulsified oil in water mixture was measured and compared with the transmission of a set of standards to give the apparent oil content. The oil droplet size distribution was also measured by photomicrography of the sample as it passed through a flow cell. The problem of differentiating between hydrocarbons from algae and man-made sources was tackled by Lysyj and Newton (2221) who used a pyrolysis technique followed by gas chromatography to give a unique fingerprint for algae residues and outboard motor oil. Millard and Arvesen (2521) and Ahmadjian and Brown (81) both investigated the feasibility of remote detection of pollutants and oil slicks. The latter procedure uses laser excited Raman spectra to record the spectra a t a distance of 21 feet from the sample, whereas Millard and Arvesen used a variety of techniques to locate oil slicks from the air. The most promising technique appears to be differential polarization. A number of authors reported on procedures for the determination of hydrocarbons in air. Shadoff et al. (3241) reported on the problems of analyzing for sub ppm amounts of organics in air. Waksmundzki and his coworkers (3761) used series columns of 5% Tri cyanoethoxy-propane and 5% polyethylene glycol 400 on N.A.W. Chromosorb W. to separate methyl and ethyl acetates, l-propanol, acetone, benzene, toluene, and xylene and six other common solvent constituents. Hyde (1561) reported the simultaneous determination of benzene, toluene, xylene, and ethylbenzene in air by gas chromatography. Automatic analyses for trace contaminants are coming into vogue as indicated by the instrument patented by Beckman (261) and the chromatograph reported by Liebe (2091). The problems of calibrating these trace gas analyzers were well covered by DeMaio (691) who gives calibration procedures using permeation tubes. The method of preparation of these tubes is well described. An analytical guide report by the American Industrial Hygiene Association (121) comprehensively covers recommended concentration levels and methods of analysis for styrene in air. Activity in the area of automobile exhausts shows an interest in the determination of carcinogenic polycyclic aromatic hydrocarbons. Gladen (1221) cooled the exhaust and then filtered it through a paper filter followed by silica gel. The filter system was washed with cyclohexane and, after a potassium carbonate wash, the cyclohexane solution was chromatographed on Sephadex LM 20, using isopropanol as eluant. Grimmer and his coworkers in a series of papers (1271-1291) reported on sampling systems and the analysis of polycyclic aromatics in exhausts. After preliminary s e p d ration on Sephadex LM 20, the enriched hydrocarbon fractions were analyzed on an OV 101 or OV 17 50-meter stainless steel capillary. The 59 polycyclic aromatics were identified by retention time. The procedure is reported to be 190R
applicable to industrial flue gases as well as automobile exhausts. A procedure for the determination of polycyclic aromatic hydrocarbons in industrial waste including gases, liquids, and dust was reported by Stepanova et al. (3491). The sample is extracted with benzene by a technique appropriate to the sample phase, and then the benzene extracts are subjected to TLC on alumina using light petroleum 40" to 70" cut as developing solvent. UV fluorescing spots are extracted with benzene-octane and determined fluorimetrically a t -196 "C. Techniques reported by Midkiff et al. (2491) for the determination of traces of petroleum products in suspected arson cases has wider application. The techniques used are head space analysis of the sample in a sealed jar or vessel, and CC14 or dodecane extraction followed by gas chromatography on a 20-foot X 0.125-inch stainless steel column. The procedures were applied to a variety of samples including an oily rag and soil. Krieger et al. (1891) reported on studies on the chemiluminescence reactions of oxygen with light hydrocarbons. The spectra of methane, ethane, propane, ethene, propene, trans- butene, acetylene, and formaldehyde were determined. It was suggested that the technique could be applied to the determination of these compounds in the atmosphere. Grimmer (1251) developed a solvent partition technique using cyclohexane-methanol to concentrate polycyclic aromatics. The compounds were then separated by capillary gas chromatography on an OV 101 column (50 meters X 0.5 mm). The technique was applied to atmospheric dust, car exhaust gases, and cigarette smoke. Gas Chromatography. As usual there are a vast number of publications concerned with the use of gas chromatography in the analysis of hydrocarbons. The application of gas chromatography in the Petroleum Industry was reviewed by Ramond (2961). Another review by Petrov et al. (2841) paid particular attention to cyclic hydrocarbons. Yanovskii et al. (3871) proposed performance criteria based on the separation efficiency and analysis time. Harris (1391) discussed the problems associated with the injection of large samples. A symposium held on the applications of gas chromatography and associated techniques (1591) contained many articles of interest. Papers dealing with gas chromatographic theory and specific applications are well represented. The role of the stationary phase in gas chromatography has been studied by Bruner et al. (461) who investigated the changes in the heat of adsorption, separation factors, HETP, and retention properties, for hydrocarbons and alcohols when small amounts of stationary phases were added to an adsorbent. Hollis (1511) surveyed the use of porous polymers for gas and liquid chromatography. Guha et al. (1331) investigated the behavior of 2,2,4-trimethyl-pentane on n-octane on Poropak P. The branched chain peak broadening phenomena has been explained as being due to restricted intra particle diffusion. Langer (2011) investigated tetrachloroterephthaloyl oligomers as liquid phases for gas chromatography. He reports that bis(4-carbopropoxy-2,3,5,6-tetrachlorobenzoyloxy-3-propyl) tetrachloroterephthalate shows excellent meta para selectivity for the xylenes. Modifications to supports is a current topic of interest. Fuller (1091) prepared supports by forming a polymer on a support. The resultant material was capable of providing greater column efficiency for the separation of light hydrocarbons than was achieved with porous polymer beads. Guillemin et al. (1361) studied the effect on retention times when the activator temperature, specific surface area, and
ANALYTICAL CHEMISTRY. VOL. 4 7 , NO. 5 , APRIL 1975
porosity, of Spherosil micro-beads were changed. Aue et al. (161) prepared modified wide pore silica gels which give improved separation of n-alkanes. Saunders et al. (3151) prepared silica phases bonded with sulfobenzyl groups that were particularly useful for the separation of unsaturated hydrocarbons. Sawatsky et al. (3161) evaluated lithium chloride coated porous silica for the separation of dialkyl and alkyl aryl sulfides from polycyclic aromatic compounds. Schwartz et al. (3221) prepared satisfactory columns using a spherical attrition resistant alumina, PS 1 as support. Aue et al. (171) prepared bonded monomolecular polymer films on silica supports and found them useable for the rapid separation of closely related polar compounds. Belyakova et al. (261) proposed the use of barium sulfate for the gas solid chromatography of C5 t o Clo n-alkanes and CG-CS arenes. Mathur et al. (2421) studied a number of modified aluminas and silica gels for the analysis of light hydrocarbons. Bruening e t al. (441) prepared silica-containing polymers by treating silica with diethylene glycol and reacting the resultant ester with diisocyanate. The phases are useable for the separation of gaseous and c 5 - C ~ saturated hydrocarbons, and light naphtha. Vernon (3681) studied the behavior of alkyl benzenes and polycyclic hydrocarbons on a sodium treated alumina. Moolchandra et al. (2551) used a modified attapulgite as a chromatographic support. The support with appropriate stationary phases was used to separate a wide variety of hydrocarbons. Attapulgite is reported to be less versatile than diatomaceous earth. Sakodinskii et al. (3121) prepared polyimide compounds that are useful for the separation of high boiling aromatic hydrocarbons. Marik et al. (2361) investigated the use of the urea inclusion compounds containing n-octane or n-decane. Separations of isomers such as 4- and 2-methyl heptane were demonstrated. Clathrate compounds of the type Ri(4-picoline)4(SCN)zO 6Q where Q = quinole or benzoic acid were used by Sybilska et al. (3571) to successfully separate the 0-, m-, p-xylenes, ethyl benzene, and 0- and p-diethyl benzenes. Polyvinyl chloride powder is reported by Jamieson (1661) to be extremely effective in selectively retaining aromatic compounds in a mixture of n-, iso-, and cycloalkanes. The selectivity is reported similar to that exhibited by molecular sieve 5A in separating n-alkanes and aromatics, except that with PVC it is the aromatic compound that is retained. Guillot et al. (1371) prepared a polyphenylsiloxane which gave very good results for the separation of alkanes in the presence of alcohols. The material is useable up to 420 "C. Charge transfer complexes and their use for the separation of olefins were reviewed by Guha et al. (1341). Schurig e t al. (3211) reported on the use of rhodium compounds for olefin separation as did Gil-Av e t al. (1191). Malan et al. (2321) described a sampling system for the analysis of C1 to C j hydrocarbons. The method relies on the expansion of the mixture into a known volume. Teleshova et al. (3601) heated samples in order to bring them into the gaseous phase before injection. Dunlop et al. (851) described a modification of the indium tube technique for the injection of light hydrocarbons and reports that the reproducibility of the results was better than when a gastight syringe was used. Folmer (1031) introduced a syringe dilution method for calibration of a gas chromatograph for the analysis of gases. Bogomolets et al. (351) reported that only sampling under pressure in special metal containers resulted in reliable determination of Cj+ hydrocarbons in natural gas. An apparatus was reported (401) for the rapid analysis of methane, ethane, propane, and butanes in natural gas. The separation was achieved in seven seconds.
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Ottenstein et al. (2711) reviewed the analysis of light hydrocarbons, permanent gases, and reactive gases on carbon molecular sieves. Raulin et al. (3011) reported that @,@'oxydipropionitrile chemically bonded to the siliceous support is effective for the analysis of C1-C4 hydrocarbons and Cl-Cd alkane-thiols and sulfides. Carson et al. (511) reported that 28 C I - C ~hydrocarbons in butadiene process streams could be analyzed on series columns of 20% dibutyl maleate and 10% bis(2-methoxyethoxy)ethyl ether on Chromosorb P. Lulova et al. (2201) separated and determined 1,3-butadiene in isobutane-isobutene mixtures. Kladnig ( 1 8 - 3 ) separated 1-butene, isobutene, trans-, and cis-butene, in less than 10 minutes on a 20% Propylene Carbonate column a t 0 "C. The analysis of C1 to Cg hydrocarbons in petroleum streams was also reported by Kachlik-Olasinka (1741), Turowska et al. (3641), and Stepanova et al. (3481). Bruner et al. (451) separated mixtures of ethane, propane, butane, and the deuterium- and tritium-containing analogs on a squalane on Sterling FT carbon black column. Genty (1171) also studied the analysis of the deuteriumand tritium-containing propane analogs and showed that, by the use of statistical techniques, it is possible t o determine the isotopic ratios of the mixture as a whole. The precision attainable in hydrocarbon analysis was reported by the International Conference on Benzole Producers (1071). Comparative molar response factors were reported by Carson et al. (521) which are reported to be in good agreement with previously published data. The problems of accurate quantitative analysis of overlapped peaks was investigated by Macnaughton et al. (2261) who used a series of n-alkanes, and benzene and perdeuterobenzene, to develop a principal component method of peak deconvolution. Stavinoha et al. (3461) reported a method for the isolation and determination of aromatics in gasoline by means of a multi-oven, multi-column technique. The procedure was later improved by the use of an internal standard (3471). Aliev et al. (111) used a multiple calculation and standard method to determine the group composition of light fractions of cracking gasoline. The chromatographic analysis of naphtha and catalytic reformate was reported by Bryanskaya et al. (491). Belopol'skaya et al. (251) reported that paraffinic and naphthenic hydrocarbons could be separated on thiodipropionitrile. Diskina et al. (781) analyzed straight run gasolines for aromatic compounds and compared the results with the aniline point of the cuts. Il'icheva et al. (1571) determined the aromatic hydrocarbons in Romaskinko petroleum fractions by chromatography on polyethylene glycol 1500. Kuchhal et al. (1901) reported that the c6-Clo aromatic hydrocarbons can be analyzed rapidly in C1-C12 hydrocarbon mixtures on 1,2,3,4,5,6-hexabis(cyanothoxy)hexane.Mukhopadhyay (2571) analyzed the reformate from the reforming of naphtha fractions on type AP-64 platinum catalyst. The c8-c13 aromatic hydrocarbons in Uzbek petroleum were analyzed by Khodzhaev et al. (1821) who identified 29 compounds out of the 35 found. Galtieri et al. (1131) used a bentone-34 isodecylphthalate column to determine styrene, dicyclopentadiene, a-methyl styrene, 0 - , m-, and p-methyl styrene, idene, and methyl idene in steam cracked naphtha. An exhaustive study of column materials for the separation of the isomeric xylenes was performed by Deur-Siftar et al. (731). The best separation was obtained on a mixed bentone 34/dinonylphthalate/GE SF-96 silicone oil on Chromosorb P column. Peter et al. (2811) reported on the procedures used for the purity control of an aromatic extraction unit. The anal-
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ysis of xylene production products was reported by Shepot’ko et al. (3271). The direct analysis of polycyclic aromatics in carbon black was reported by di Lorenzo (2161) who used a solids injector to inject the carbon black directly into the chromatograph. The analysis of polycyclic aromatics was also reported by Lane et al. (20011, Grimmer (1261),Jedrychowska (1691),and Frycka (1081) who used carbon black dispersed on Chromosorb W as the separating adsorbent. Saha et al. (3111) used a pair of column systems to first separate fractions of naphtha by preparative gas chromatography, and then to resolve the components on a pair of analytical columns. Squalane and tetracyanoethylated pentaerythritol were found to be particularly suitable as stationary phases. Petrov et al. (2851) identified twenty-four Cg-Czs branched chain alkanes of an isoprenoid structure in gas oil fractions of crude oils. Diskina et al. (751)also analyzed gas oil fractions for saturated and aromatic hydrocarbons. Folmer (1041) reported a simple method for separating normal and isoparaffins, which consists of a splitter a t the end of the analysis column. Half of the effluent flows via a 5A molecular sieve column to the detector, the other half via a dummy adsorber containing celite to the other detector of a dual flame ionization instrument. The electrical difference in the flame ionization detector responses represents the normal paraffins. Selective adsorption of n-alkanes on 5A molecular sieve was also used by Suto et al. (3531). Stuckey (3521) used Folmers method (ibid.) to analyze kerosines and crude oil heavy distillates for normal paraffins. A subtractive method using 5A molecular sieve to remove the n-alkane was reported by Nigam et al. (2591) for the analysis of high purity heptane and cetane. The analysis of various materials for n-alkanes was reported by Postnov et al. (2911),Nigam et al. (2611),Rudakova et al. (3081),and Vollert et al. (3721). Nonaka (2621) reported on a number of gas-solid chromatography separations using alumina with steam as the carrier gas. Using Chromsorb P as the support, polycyclic aromatics a t a concentration of 10 ppm to 0.01% in water can be determined (2631). Bardyshev et al. (211) evaluated 60 stationary phases for the separation of terpene hydrocarbons. The best were vacuum oil VM-4, tricresyl phosphate, and polyethylene glycol 2000. Petkova et al. (2831)reported that the direct determination of cyclopentadiene and dicyclopentadiene in pyrolysis naphtha using a two-column system gave better results than a previous method which relied on the complete conversion of cyclopentadiene to the dimer. Pilt et al. (2871)reported that the normal CS-c11 alkynes can be separated by gas-solid chromatography on graphitized carbon black. The isomeric alkynes were not completely separated. The extent of separation depended on the geometric configuration, the position of the multiple bond, and the number of carbon atoms. A two-column system comprising a 12-ft X 0.125-in. column containing 15% seven-ring polyphenylether on 60 to 70 mesh Anakrom ABS and a 5-ft. X 0.125-in. column containing 1.5%of SE-30 on F-20 alumina was used by Willis (3791) to separate the C1 through C7 containing off gas from hydrocarbon pyrolysis. The analysis of chlorinated hydrocarbons in gasoline was reported by Castello et al. (551). Takano et al. (3581) reported that the addition of a sulfuric acid treatment step, to remove aromatics and nitrogen compounds, assists in the accurate analysis of polychlorinated biphenyls in lubri192R
cating oil. The chemical removal of fatty alcohols by means of a Grignard reagent was used by Vasilescu et al. (3671)to improve the analysis of hydrocarbons in fatty alcohols. A considerable interest was shown in the selective separations possible with molecular sieves. Peterson et al. (2821) used a column system consisting of molecular sieve 5A (90-mm X 4.8-mm) and molecular sieve 13X (1-meter X 3-mm i.d.) to separate naphthenes, iso, and normal paraffins in naphthas. McTaggert et al. reported on several aspects of the analysis of naphthas (2281),olefinic gasoline (2271), and the apparatus necessary for the hydrocarbon type analysis on molecular sieves (2291).Other authors reported on adsorption effects on 13X sieves when performing the paraffin naphthene separation ( I O Z ) , and reported results of naphtha analyses (1141). Deur-Siftar et al. (741) reported that a short precolumn of 5A molecular sieve could be used to retain n-alkanes and n-olefins and thus simplify the analysis of hydrocarbons in petroleum fractions. Breshchenko e t al. (391)used a similar technique for kerosines. Eisen et al. (921) investigated the O alkanes on graphitized carseparation of c6 to C ~ normal bon black. The cis isomers elute before the corresponding trans isomers. The extent of separation of the isomers increased in the order alk-3, alk-2, alk-4, and alk-5-enes. The use of macroreticular cation exchange resins for the selective analysis of hydrocarbon types was investigated by Hirsch et al. (1501).These resins are highly absorptive for hydrocarbons, and the silver ion form retains aromatic and olefinic compounds strongly. The preparation (2531) and chromatographic use of zeolites for the selective separation of p-xylene was claimed, as was the preparative scale separation of p-xylene in a mixture of xylene isomers (2541)in British Patents. Deans et al. (681) reported a number of methods for adjusting the separation characteristics of two different columns in series. Mieure (2501) described an inter-column detector technique for continuously monitoring the effluent from a pre-column in a column system using the same flow techniques. Eppert (961) claimed an apparatus especially useful for the analysis of high boiling mixtures, containing interfering substances. The use of computer techniques was represented by the use of a computer for selecting the most suitable liquid phase (181);for the real time processing and interpretation of complex chromatograms (1021); for the prediction of compound structure from retention data (59Z),and the accurate and precise calculation of the fractional composition of petroleum fractions (3851). Rion et al. (3021) reported the modification of an integrator so that simulated distillation data could be obtained. Lasa et al. (2021) reported a nickel-63 based argon detector which is sensitive down to 1 pg per second of benzene and pentane. Capillary Gas Chromatography. The use of high resolution gas chromatographic columns, mostly wall coated open tubular but also support coated and packed capillaries continues to grow. Interestingly, the range of stationary phases reported was not large. Sidorov et al. (3321)published an extensive review of the application of capillary gas-liquid chromatography to complex mixtures, particularly hydrocarbon fractions. Techniques for achieving a desired film thickness and the effect of the liquid film thickness on the capacity ratios for benzene were reported by Bartle (221).Evrard et al. (971) developed a technique in which the column is preceded by a shorter, pre-column of 4-mm i.d. The system is particularly suitable for the analysis of traces of high boiling materials in a volatile matrix. The sample is injected onto the packed pre-column, the volatile material allowed to evaporate, and
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then the sample residue is transferred to the cooled capillary column by progressive heating of the pre-column. An automated system used for the analysis of alkanes is described. Nikelly (2601) compared the separations obtained on support coated open tubular columns with those obtained on porous larger open tubular columns. Benzene, toluene, and the three xylenes, were resolved a t 75 "C in 18 minutes on a column coated with Chromosorb R b 470-1, m-bis(mphenoxyphen0xy)benzene and Inepal CO-880. The most popular stationary phase used for capillary gas chromatography of hydrocarbons was squalane. Applications by Shefter et al. (3251) cover the distribution of over 190 paraffinic and naphthenic compounds in the straight run naphtha from 5 USSR crudes. Bogdanchikov e t al. (361) used a 70-meter squalane capillary to study the gasoline fractions of some petroleums from the Komi region. Relative retention data was reported by Kulikov et al. (1951) for 63 hydrocarbons in a 50-125 "C boiling range fraction. Nakamura (2581) used a 90-meter squalane column and identified 200 components out of 280 peaks separated from a sample of catalytic cracked gasoline. All the individual straight chain dodecanes and the more important alkyl aromatics produced by the catalytic dehydrogenation of dodecane were separated on a 200-meter by a 0.2-mm i.d. squalane column by Sojak e t al. (3391). The same column was used by Sojak e t al. (3411) to separate all 85 of the theoretically possible linear alkenes up t o C14; and to examine the dehydrogenation products of undecane (3401).
Other separations of petroleum fractions were reported on a hexadecane capillary (150-m X 0.02-in. i.d.) by Galtieri (1121) and on Apiezon M (30-m X 0.5-mm) by Fedyanin (981). Doering and his coworkers reported on the separation of the dehydrogenation products of C1o-CI4 paraffins (811, 831). The analysis of Cg and C7 cycloalkyl chlorides, cycloolefins, methylcycloalkanes and bicyclo [n.1.01 alkanes was accomplished by Dupuy et al. (861). A satisfactory separation was achieved on a 50-meter X 0.25-mm 0.d. stainless steel capillary coated with MS-550. Lipshtein et al. (2111) studied the analysis of a olefin and secondary alkyl benzene fractions on an SE-30 capillary column. The average quadratic error and sensitivity were 4 and 0.05%, respectively. The use of tetrachlorophthalates as stationary phases for the separation of C7 to Clo n-alkenes was reported by Ryba (3091). The CS to C11 n-alkenes were analyzed qualitatively and quantitatively on 7,8-benzoquinoline for the n-decenes and n-undecenes, and on a 3:l mixture of 7:8 and 5:6 benzoquinoline for the n-octenes and n-nonenes by Meltzow et al. (2471). Doering et al. (821) converted the C13 alkenes to the epoxides by reaction with perbenzoic acid and then separated the epoxides on a 300-m X 0.25-mm glass column coated with UCON-LB-550X on a Carbowax 20M treated surface. Diskina et al. (761) determined the individual aromatic hydrocarbons in gasoline fractions boiling in the 120 to 200 "C range by gas chromatography on a 50-meter capillary coated with tricresylphosphate. The composition of a 160 to 190 "C hydroreforming stock was analyzed by Diskina e t al. (771) on a similar column using n-undecane as internal standard. Dinonyl phthalate columns were used by Mamedaliev et al. (2331) to study the composition of Ca and C9 pyrolysis naphtha fractions. Packed capillaries (%meter x 1-mm i d . ) were used by Talalaev and his coworkers (3591) for the analysis of C23 to C48 n-alkanes recovered from a crude distillate by urea inclusion. Grushka et al. (1321) reported on the use of p-azoxyani-
sole liquid crystals as stationary phases for gas chromatography. Good separation of p - and m-xylene was achieved. P r e p a r a t i v e Scale G a s Chromatography. Gelpi e t al. (1161) described an automatic preparative gas chromatograph that was used to prepare milligram quantities of steranes and triterpanes isolated from Green River Formation Oil Shale. Bickford et al. (321) used a modified preparative gas chromatograph as an aid in determining the molecular types in 300 pl of gasoline fractions or cracked stocks. Reaction Gas Chromatography. The use of reaction during analysis to aid in chromatographic separation or identification was the subject of several papers. Herian et al. (1431, 1441) compared a reactor furnace and a ribbon type pyrolysis probe for the analysis of gasoline type hydrocarbons. The major effect on the repeatability of the pyrogram was caused by the variation in furnace temperature. A packed pyrolysis reactor was used by Higgins e t al. (1461) who used a quartz tube packed with iron, 6.2% iron on Chromosorb W, quartz wool, and graphite. The extent of pyrolysis of hexane, 2,2-dimethylbutane, and 2,3-dimethylbutane, a t 600-750 "C and the product distribution, varied with the packing. Araki and his co-workers (141) pyrolyzed alkylbenzenes on alumina a t 550 "C. The position of the phenyl group could be determined by comparing the areas of the characteristic peaks in the pyrogram. The analysis of naphthenes by dehydrogenation to aromatics was the subject of a patent (3611) and the procedure used by Goryaeva et al. (1241) for the analysis of naphthenes in a gasoline fraction, by Ivanov et al. (1621) for the analysis of shale oil fractions and by Diskina et al. (791) for the group analysis of ligroin fractions. Ohtaki and his coworkers (2701) used a hydroborationgas chromatographic method to determine alkanes in the presence of olefins. The terminal alcohol of non-terminal alcohol content was indicative of the ratio of a olefins to inner olefins. The technique was later extended (2741) to a hydroboration-methanolysis procedure for the determination of olefins as a group. The amount of olefin was determined by the volume of evolved hydrogen. Kugecheva et al. (1911) used selective reduction on a palladium catalyst followed by adsorption of acetylenes with a silver nitrate on Chromosorp P. The chromatographic identification of 14 acetylenes and dienes in pyrolysis products was achieved. Soulages et al. (3441) developed a method for the analysis of saturates, aromatics, and olefins in fractions with a boiling point of less than 200 "C by selective adsorption of aromatics on Hg(ClO&-HC104 and olefins on HgS04HzS04. The analysis using a flame ionization detector takes approximately 5 minutes. Chromatographic Component Identification. Identification of components in a mixture by their chromatographic behavior is a subject that draws much attention from European authors and yet is largely ignored in the United States. Rohrschneider (3071) surveyed the empirical relationships and approximate regularities in retention behavior. Hartkopf (1401) in reviewing the Rohrschneider approach for characterizing gas chromatographic liquid phases shows that dispersion, dipole orientation, and hydrogen bonding are the main types of solute-solvent interactions in gas-liquid chromatography. Ladon et al. (1991) showed that the James-Martin Rule, i.e., the relationship between the carbon number of members of a homologous series and the logarithm of their chromatographic retention times, can be extended in some cases beyond the bounds of a single series. The validity of the extended equation was confirmed
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by tests on 38 alkanes, 18 cycloalkanes, 58 alkenes, 5 cycloalkenes, and 8 alkadienes on three stationary phases. Saha (3101) commented on the sub-classification of aromatic compounds by the temperature coefficient of the retention index. Schomburg et al. made exhaustive use of the Kovats index approach to identify alkanes, alkenes, and alkadienes in a gasoline cut (3181) by table matching and incremental prediction from data on other compounds in a homologous series. They also published an extensive tabulation of retention data for saturated and unsaturated cyclopropane hydrocarbons. Janak et al. (1671) concluded, based on published retention indices of all 85 straight chain alkenes up to C14, that the Kovats index increments of homologous series depend on the position and geometry of the double bond and become constant and equal only when the chain length to the double bond was a t least seven carbons, Le., starting with cis- or trans-tetradec-7-ene. The retention indices of cycloalkanes, cycloalkenes, bicycloalkyls, cycloalkylalkenes, and bicycloalkenes were reported by Besson et al. (311) on seven stationary phases. Fonkich et al. (1051) gave similar data for twenty c 7 - C ~alkanes and nine Cs olefins. Louis (2171) used a retention index scale based on alkyl benzenes for the identification of aromatic hydrocarbons separated on a 50-meter X 0.25-mm steel capillary coated with 1,2,3-tris(2-cyanoethoxy)propane. The retention indices of 300 C7-Cz4 alkanes on Apiezon L were reported by Rappoport (2971). Sojak et al. (3421) determined the retention indices of alkenes and Ce-Cll alkyl benzenes on squalane and polyethylene glycol. Howery (1541) factor analyzed a data matrix of 25 hydrocarbons on 12 stationary phases. Nine solute factors of physical significance were found. Other uses of retention indices for identification of hydrocarbons include the identification of alkenes, cyclopentenes, and cyclohexenes by Eisen e t al. ( 9 3 0 , and an extension of Schomburg’s approach (ibid.)by Hoshikawa to Clo alkanes (1521). Shlyakhov et al. (3291) used Kovats indices, the peak separation parameter for C23/C24, and relative retention times to identify n-alkanes. The reproducibility with which retention indices can be determined was the subject of papers by Kulikov et al. (1951) and Pacokova e t al. (2751). Guichard-Loudet (1351) reported on a computer procedure for identifying compounds from their chromatographic retention times. Identification according to boiling point was used by Turowska et al. (3641) for identifying hydrocarbons in natural gas. Sojak e t al. (3401) show that the approximate relationship between boiling points and retention indices exhibits several significant exceptions for the separation of hydrocarbon isomers on a squalane column. Calculation of retention index values and the temperature dependence of the indices from molecular structure and physical properties was reported by Castello and his coworkers (561, 571). Dimov et al. (801) compared the physicochemical retention indices, calculated from the vapor pressure and molecular volume, with the chromatographic retention indices determined on squalane and found them to be in good agreement. Jaeschke et al. (1651) described an automatic chromatograph which allows for the identification of unknown compounds by reference to a Kovats index calibration mixture of C5 to ClS normal alkanes which is also analyzed auto\ matically. Mass Spectroscopy. Interest in mass spectroscopy covers a broad field of endeavor ranging from group analysis to the mass spectra of discrete components. Rasmussen et al. (2981) reported a procedure for determining condensable 194R
materials in a non-condensable matrix. The condensable materials, e.g., HzS, COS, SOz, thiols, and hydrocarbons were separated from an inert gas matrix by collection under vacuum in a liquid nitrogen cooled trap. The condensate was then allowed to expand into the inlet of the mass spectrometer. Calibration curves are constructed for each component over the determinable concentration range to correct for adsorption effects. With the use of a 20-mi sample, the detection limit is E 1 ppm and errors are generally < f10% a t the 5-ppm level. Pebler et al. (2771) also used a cryogenic trap technique to freeze out traces of gaseous impurities in inorganic gases. Sub-ppm level determinations carried out include hydrogen, nitrogen, oxygen, argon, and carbon dioxide in liquid helium; and carbon monoxide, carbon dioxide, and hydrocarbons in hydrogen. Rasmussen (2991) used a direct injection technique for the analysis of high pressure gasoline streams containing light ends. A gas chromatographic analysis for C5 and lighter hydrocarbons was used to mathematically depentanize the sample. The reported repeatability a t the 95% confidence level when applied to reformer product was 0.6% which is significantly better than the 2.4% obtained by the conventional ASTM D-2789 procedure. Hippe et al. (1471) attempted to apply field-ionization mass spectrometry to the quantitative group analysis of hydrocarbon mixtures. They report that the spectra do not appear to be linear superpositions of the spectra of the individual components and that the molecular ion intensities of each component depend on the sample matrix, thus careful calibration is required. Kinder (1841) also investigated hydrocarbon type analysis by mass spectrometry. He studied the relationship between the total ion current and sample pressure, weight, and volume. He reports that the total ionization per unit of paraffins, monocyclo paraffins, monoolefins, and alkyl benzenes is more closely related to volume than either pressure or weight. A procedure developed by Robinson (3031) extensively covers the hydrocarbon range of interest (200 to 1100 O F ) with a procedure for the analysis of saturate and aromatic types by low resolution mass spectrometry. The entire composition is accounted for in terms of 4 saturated, 12 aromatic hydrocarbon types, 3 thiophens, and 6 unidentified aromatic types. Pyrolysis gasolines were analyzed by Rasmussen et al. (3001) using a low voltage technique. Concentrations of styrene, and C5-C12 monolefins, diolefins, cycloolefins, alkyl benzenes, indanes, and naphthalenes were reported which agree well with the Fluorescent Indicator Adsorption method and the conventional 70 eu mass spectrometric method. Heavier hydrocarbon fractions also received their share of attention. Aczel et al. (31) reported on the detailed characterization of gas oils by both high and low resolution mass spectrometry. A very exhaustive procedure involving separation of the gas oils into saturate, aromatic, and polar groups followed by gas chromatographic distillation and mass spectrometric analyses of 100 OF wide fractions of each type were reported. The method is claimed to be applicable to crudes, coal liquids, shale oils, and refinery streams boiling up to 1200 OF. Severin et al. (3231) also reported on a method for the analysis of high boiling fractions, in this case by a parent ion method using 10 eu electron impulse and field ionization techniques. The 85 paraffins, naphthenes, and aromatics of 134-506 mol wt were used to derive estimation equations. The method was applied to 10 lubricating oils of a predominantly naphthenic nature. Correlations with various molecular parameters were derived. The problems associated with non-petroleum hydrocarbon samples are beginning to receive attention as
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
evidenced by the paper by Swansiger and his coworkers (3541) who reported a group type analysis procedure for 17 hydrocarbon types found in the aromatic fraction of a liquid coal product. A review article by Aczel (21) also covers coal derivatives as well as petroleum products. The article covers high applications of high resolution mass spectrometry with particular reference to aromatics and polar materials. A second article (41) describes the high resolution low voltage techniques used with computer data processing. Typical results are given in this paper. Various applications of computer processing techniques range from the use of a small computer to compact data for latter processing on a larger computer, as reported by Engelmann et al. (951) to the application of pattern-separation techniques, which was used by Tunnicliff e t al. (3631) to calculate the average properties of gasoline samples. Other applications include a “correlation set” approach as used by Smith (3361)and the use of successive pattern recognition based on the peaks with the highest information level as reported by Khots (1831). Studies aimed a t improving the precision of the ratio of peak intensity in high resolution mass spectrometry were reported by Brown et al. (431).The biggest variable was the temperature of the ion source. A contribution to extending the application of mass spectrometry to hydroaromatic compounds was reported by Shultz e t al. (3311) who showed that the sensitivities of such compounds can be inferred from the sensitivities of the parent aromatic ring compounds. A method published by Brodskii (421) provides a set of linear equations for the analysis of aromatic compounds containing a t least 3 or 4 carbon atoms in the side chain. The method was verified on synthetic mixtures of 23 groups of aromatic hydrocarbons. The analysis of the aromatic carbon fraction of Korobkov and Zhirnov petroleum crude was reported by Kuklinskii (1941).The aromatic hydrocarbons consisted mainly of mixed structures with naphthenic rings and aliphatic side chains, which increased with increasing boiling point, predominating. The mass spectrometric study of some saturated bridged tricyclic hydrocarbons, such as methyl substituted perhydrotricyclopentadienes were reported by Denisov (711),other authors reported studies on alkyladamantanes (2881)and the stereoisomeric bicyclo[4.4.0]decanes (2191). Karasek et al. (1771) studied the similiarities between the chemical ionization mass spectra of n-alkanes and nalkyl halides and the plasma chromatographic mobility spectra of these compounds. Gas Chromatography-Mass Spectrometry. With the wealth of experience in the petroleum industry in the use of these two techniques, it was somewhat surprising that so few papers were published covering the application of the combined techniques to hydrocarbon materials. Bruner et al. (471) described a modification to a conventional mass spectrometer for use as a GC/MS system. The efficiency of the system was examined in respect to chromatographic efficiency and mass spectrometric sensitivity and resolution by the analysis of a CS-Cg hydrocarbon mixture. The use of an electrochemical cell using a 7 5 2 5 palladium silver tube as anode was demonstrated by Dencker e t al. (701). The separator was used for the analysis of a seventeen-component mixture containing furans, n-alkanes, aromatics, and alkanes. I t is reported that conjugated double and triple bonds are hydrogenated in the anode but unconjugated double bonds are not. Rabinovich et al. (2951)measured the relative intensities of the most common peaks in mass spectra of organic compounds and suggest that the ratio of the peak intensities
and 141/Z43, where 1 3 9 is the peak intensity a t mle = 39; 1 4 1 a t mle = 41, etc. . . . , can be used for identifying members of a homologous series. The compounds studied include thiophenes and alkyl benzenes. By hydrogenating alkyl benzenes, Lindeman (2101) prepared mixtures of the cis and trans isomers of the corresponding alkyl cyclohexanes. These materials were analyzed by GC/mass spectrometry. The chromatographic retention data and the mass spectra of the individual isomers are given. Gallegos (1101) identified 23 mono- and one diaromatic phenyl cycloalkane isolated from Green River shale, and Santoro (3131) used GC/MS for identifying components of virgin naphtha. A microreactor was used to thermally crack components. The thermally cracked products were identified by GC/MS. The coupling of a high resolution, usually capillary, column with a mass spectrometer is a particularly powerful identification tool as is evidenced by the work of Gallegos et al. (1111) who analyzed pyrolysis naphtha. Mass chromatograms of m/e 77, 71,69,67, and 65 were obtained. The analysis identified 1,3-butadiene,isobutene, but-1-ene, and the likely position of but-1-yne, 1,4-pentadiene, cyclopentadiene, cis- IJ-pentadiene, cyclopentane, and 2 methylIJ-pentadiene. Dicyclopentadiene was identified as were cross dimers of cyclopentadiene and methylcyclopentadiene. Several Cg vinyl aromatics were also identified. A 100-meter X 0.3-mm glass capillary coated with Apiezon L was used in a GC/MS system by Otvos et al. (2721)in their GC/MS investigation of industrial dodecylbenzenes. Many of the linear alkyl benzenes were identified, but samples containing branched chain isomers could only be analyzed qualitatively. Small amounts of alkyl indanes and alkyl tetralins were also detected. The use of chemical ionization spectra in a GC/MS system was reported by Blum et al. (331) in their analysis of alkene mixtures by combined capillary GC/MS. The Cg monoalkenes studied were converted to diols and then to their trimethylsilane derivatives. The molecular ion was determined by chemical ionization and the position of the double bond by conventional electron impact spectrometry. The ultimate in ultra trace analysis for C6to Czoorganic compounds was achieved by Grob et al. (1311)who concentrated the organics in air on carbon traps. The air sample was passed over two 25-mg traps in series a t 2.5 ml/min for 8 days. The organics were removed by refluxing with carbon disulfide and then separated on either a 80-meter X 0.33-mm Ucon LB 550 or a 120-meter X 0.33-mm Ucon H B 5100 column. The materials eluting from the column were analyzed by mass spectrometry and were found to be mostly from the combustion of fuel oil. The quantitative analysis of some C6 to C12 components is reported. Vykhrestyuk et al. in a series of papers reported on the GC/MS analysis of straight run petroleum fractions (3731) naphtha and its product after catalytic reforming (3741) and an aromatic fraction from aviation kerosine (3751). In each case, approximately 100 compounds were separated, using a dinonyl phthalate capillary column (100-meter X 0.3-mm i.d.), and identified by mass spectrometry. A combined GC/MS technique applied to the analysis of Isoprene concentrates was reported by Otwinowska et al. (2731).The chromatogram contained 23 peaks whereas the mass spectrometer gave discrete spectra for 27 components. In order to improve the identification, acetylenes, diolefins, and olefins were removed from the mixture by chemical means. A new technique combining liquid chromatographymass spectrometry was used by Lovins et al. (2181)to identify the eluants from the UV detector of a liquid chromato139/141
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graph. Among other examples, naphthalene, anthracene, pyrene, and chrysene were separated and their spectra recorded. Liquid Chromatography. High pressure liquid chromatography is a fast growing chromatographic technique which is being applied to the hydrocarbon field mostly in the area of polycyclic compounds. As evidenced by the interest in the technique (1581), (2401), it is likely that there will be more articles on the application of HPLC to the petroleum industry such as that by Amos (131). The theoretical aspects of HPLC have been covered by Perry (2791) and Slowik (3351). The problems of solvent selection and a selection procedure for a variety of compounds of interest to hydrocarbon chemists have been well presented by Saunders (3141). The separation of polycyclic hydrocarbons by liquid chromatography has attracted many authors. Locke and his coworkers (2131) report that modified Porosil C, specifically a naphthyl modified Porosil containing 24% w/w of organic material, exhibits selective retention of polycyclic aromatic hydrocarbons. Alumina of different activity levels was used to successfully separate a mixture of seven condensed ring aromatic hydrocarbons using hexane as eluant. The water content of the alumina, Le., its activity level, affected the resolution and analysis time. Series columns of silica gel and alumina were used by Hirsch and his coworkers (1481) to separate high boiling petroleum distillates into saturates, monoaromatics, diaromatics, and polyaromatic-polar compounds. They report that little cross-contamination was found. Lloyd (2121) used neutral grade alumina to separate spectrofluorescing compounds from automobile engine oils. The compounds were mainly polycyclic aromatic and alkylated benzo- and dibenzothiophenes. The group separation of polymethyl benzenes and polymethyl naphthalenes and their exhaustively hydrogenated products was achieved on 01 alumina containing 2.3% water by Chumakov et al. (621). Martin (2391) similarily separated several groups of cyclic hydrocarbons from steam cracker effluent on an alumina column with heptane as mobile phase. The adsorption of 3 acidic and 3 basic nitrogencontaining hetero-cyclics on alumina has been measured by Pop1 et al. (2901).The results show that the best separation of nitrogen-containing bases from areas will be obtained on acidic alumina with pentane-dichloromethane as eluant. The use of cellulose acelate column was proposed by Klimisch (1861, 1871) to give efficient, quantitative separation of benzo[a]pyrene, benzo[e]pyrene, and caronene. Sleight (3341) studied the behavior of aromatic hydrocarbons on Zipax Permaphase ODS with water-methanol mixed solvents. He reports that the retention is primarily a function of the number of rings in the molecule with secondary effects caused by aliphatic substituents. Polycyclic aromatics on cellulose acetate or Durapak OPN was the subject of a paper by Ives et al. (1631). A high sensitivity system described by Strubert (3501) was used to separate and detect fused ring aromatic compounds on 4-8 pm Spherosil XOA 400. The detection limit was 2 ng or 10 ppb. Loheac et al. (2141) reported on the separation of complex mixtures containing polynuclear aromatics using mixed silicic acid and alumina as adsorbent. They report that the use of the mixed adsorbents permits the separation to be achieved rapidly. Karger et al. (1781) used Corasil I impregnated with 2,4,7-trinitrofluorenone.Polynuclear aromatic 3- to 7-ring structures were separated. A 3-meter column containing 0.06% Trinitrofluorenone separated benzene, anthracene, pyrene, chrysene, 1,2-, and 3,4-benzpyrene, 1,2,3,4-dibenzanthracene,and 1,2,3,4-dibenzpyrene, 196R
with dry heptane as mobile phase. The separation of high boiling petroleum distillates is receiving a lot of attention. Kajdas (1751) reported on the successful use of 13X molecular sieve to separate an aromatic fraction into monocyclanobenzenes and polycyclanobenzenes. A systematic procedure was reported by Jewel1 and his coworkers (1721, 1731) who developed a procedure for isolating the aromatic hydrocarbons from high boiling distillates and residual oils. Schulz et al. (3201) used liquid adsorption chromatography in the analysis of olefin-containing naphtha range hydrocarbon products. A selective detector, based on scanning fluorescence spectrometry, for polycyclic aromatic compounds such as benzo[a]pyrene-3-methyl caronene, and perylene, was described by Pellizzari et al. (2781).Wolf (3821) proposes that large diameter (0.77- to 2.36-cm) columns have a higher separating efficiency for polycyclic hydrocarbons than do conventional HPLC analytical columns. Classical elution chromatography was used by Bodzek et al. (341) to separate 100 g of crude oil on a 1000-g silica gel column. The activity of silica gel for Fluorescent Indicator Adsorption analysis was examined by Fessler (1001). He reported that the activity of the gel is determined primarily by the conditions of precipitation and that subsequent treatment has little or no effect. He suggests that appropriate activities should be specified in the standard methods. A modified Fluorescence Indicator Adsorption procedure for the analysis of hydrocarbon types in gas oil was proposed by Mukherjee and his coworkers (2561). The procedure uses a diluent for the sample, a more viscous eluant (3:7 vol. ratio diethylene glycol-isopropanol mixture), and a high activity silica gel adsorbent. Gel Permeation Chromatography. A much under-utilized technique for preparing specific fractions of petroleum fractions is that of gel permeation. Very few papers make use of this technique to any great extent, although it is obvious from the following papers that further developments in this field could give fruitful benefits. Albaugh et al. (91) monitored the effluent from a styragel column with three detectors, a differential refractometer, UV monitor, and a flame ionization detector. Using this technique, they claimed that it was possible to detect differences between crudes, to distinguish blended bunker fuels from total crude, and to monitor changes in composition during processing. Compositional changes during processing, in this case the hydrodesulfurization of Gach Saran residue, was also the subject of a paper by Kurokawa et al. (1971) who used a cross-linked polystyrene gel with benzene as solvent to separate the components of the residue and its dehydrodesulfurized product. The fractions were further separated by solvent deasphalting, silica gel adsorption chromatography, and elution chromatography into saturates, naphthene aromatics, aromatics, and polar aromatics. Marin-Mudrovcic et al. (2371) fractionated paraffinic hydrocarbons from cycloparaffins by the number of C atoms on Sephadex LH 20 gel. McKay and Latham (2251) combined gel permeation with other techniques to isolate seven aromatic compounds from petroleum, none of which had been isolated previously. The compounds were dibenzo [b,pqr]perylene, naphthol 1,2,3,4-ghi]perylene, ben zo[pqr]naphtho[8,1,2-bcd]perylene, dibenzovg,ij]pentaphene, naphtho[l,2,3,4-def]chrysene, benzo[e]pyrene, and benzo[g]chrysene. Extensive use of gel permeation chromatography data was made by Hirsch and his coworkers (1491) who reported correlations that can be used for the accurate prediction of
ANALYTICAL CHEMISTRY, VOL. 47. NO. 5. APRIL 1975
retention volumes, molecular volumes, densities, chain lengths, and ring numbers of monoaromatic, diaromatic, and polyaromatic polar components of petroleum without resorting to further laboratory experimentation. The correlations can also be used to aid in the interpretation of mass spectrometer data of heavy distillate fractions. Thin Layer Chromatography. Thin layer chromatography appears to be being replaced by high pressure liquid chromatography in applications in the petroleum industry. Some work is still going on, however, largely dealing with polynuclear aromatic hydrocarbons. Zerbe (3931) reviewed the applications of, particularly, paper and thin layer chromatography in a review article. A was renew spray agent 8-anilinonaphthalene-1-sulfonate ported by Gitler (1211).This reagent is sprayed as a 0.1% aqueous solution on the developed plate while the plate is being viewed under long wave UV radiation. The spots containing a polar molecule fluoresce against a black background. The analysis of polynuclear aromatic hydrocarbons in petroleum was reported by Matsushita et al. (2431)who examined kerosine, fuel oil, and residual oil fractions. Twodimensional dual band thin layer chromatography was used using Alumina G and a n-hexane-ether mixture (19:l vol. ratio) as well as acetylated cellulose and methanolether-water mixture (4:4:1 vol. ratio). The ou fluorescing spots were extracted with benzene and the component analyzed by spectrofluorimetry. Compounds identified were fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[alpyrene, benzo[b]fluoranthene, benzob]fluoranthene, benzo[h]fluoranthene, perylene, indene[l,2,3-cd]pyrene and benzo[ghi]perylene. Acetylated cellulose (10% acetylated) was used by Nowacka-Barczyk (2651) to separate the benzo[a]pyrene fraction from impurities including benzo[k]fluoranthene. The separation of eleven polycyclic hydrocarbons on Silufol UV 254 precoated plates using hexane-chloroform (19:l)as solvent was reported by Thielemann (3621). The spots were located by exposure to UV radiation or by spraying with SbCls in chloroform. Two-dimensional thin layer chromatography on alumina and preparative thin layer on silica gel was used by Chatot et al. (601) to determine polycyclic aromatic hydrocarbons in atmospheric dust. The hydrocarbons were extracted from the adsorbents after separation was complete with cyclohexane. The final recoveries and the appropriate analytical correction factors are reported. The use of a familiar gas chromatographic stationary phase, Poropak T was reported by Martinu e t al. (2411) for both TLC and high pressure liquid chromatography applications. For TLC, 200-325 mesh Poropak T was coated on glass plates as a dispersion in isopropanol to a thickness of 0.5 to 0.6 mm. The coatings were used for the separation of aromatic hydrocarbons using light petroleum, carbon tetrachloride, methanol, or acetone as developing solvent. Detection was by UV fluorescence or by the quenching of fluorescence after spraying with a 0.12% solution of a,a,a’,a’tetracyanoquinodimethane in acetonitrile. R f values are reported for eight polycyclic compounds and a t least one hydrogenated derivative in each of the four solvents. Separation within each group is reported to be superior to that obtained on silica gel in the same solvent. For liquid chromatography, a 50-cm X 2-mm i.d. column was packed with 0.853 g of Poropak T. At a flow rate of 0.3 ml per minute with hexane as eluant, retention times are reported relative to naphthalene. A correlation was found between relative retention time and R f value. Spectroscopic Techniques. Infrared, NMR, both pro-
ton and C13, are well represented as are spectrofluorimetric and UV techniques. A review article by Luther (2211) covers the use of molecular spectroscopy in the analysis of petroleum products. The review covers IR and Raman techniques in particular. An article by Van Der Heyde et al. (3661) also reviews spectral techniques. Nuclear magnetic resonance techniques both carbon- 13 and proton were used by Clutter e t al. (631)to provide a direct and accurate value of “aromaticity” or aromatic carbon, as a fraction of total carbon. The high quality 13C NMR data was used to calibrate the ‘H NMR. Keefer and his coworkers (1811) used NMR in the analysis of mixtures of isomeric polynuclear hydrocarbons. The identification of the methylated derivatives of anthracene, benz[a]anthracene, benzo[c]phenanthrene, and pyrene, was made on the basis of relative chemical shifts. Coker feedstocks were examined by Grindstaff et al. (1301) who found that reduced crude and thermal cracking tar differ in the number of condensed rings and the degree of alkyl substitution. The Conradson carbon value was found to be a function of the aromaticity and the degree of alkyl substitution. NMR was used by Pave1 et al. (2761) to determine methylcyclohexadiene in high purity toluene by measuring the maleic acid anhydride adduct. Olefins were also the subject of a paper by Yamamoto and his coworkers (3861) who published charts of chemical shifts of olefinic protons. Oelert (2681) compared a number of group analysis methods and showed that the combination of NMR, IR, and elemental methods gives better results for the percentage of paraffinic, naphthenic, and aromatic carbon atoms than those obtained by the n-d-M method or several published IR and mass spectroscopic techniques. An infrared method was used by Zenker (3921) to measure the methyl and methylene peak intensities in a homologous series of n-alkanes, n-alcohols, n-aldehydes, and ncarboxylic acids. He reports that the methylene group absorptivity increases with increasing polarity of the functional group. A procedure for the quantitative determination of methyl and methylene groups in paraffin-naphthene fractions was reported by Proskuryakova et al. (2941). The results were used to evaluate the degree of branching of paraffinic chains and the presence of separate methyl groups in the structure. Leimer et al. (20411, (2051) used a near infrared method to quantitatively measure benzene, toluene, and alkanes in a mixture. Procedures are given for measuring the alkane/ toluene interferences. Kuklinskii (1941) published a procedure for the quantitative analysis of paraffin-naphthene hydrocarbons in petroleum for the concentration of methyl groups in the naphthenic ring. By means of a computer, Petzold et al. (2861) were able to compute structural group analyses for both saturate and aromatic types from complex infrared spectra. Changes occurring during the aging of light catalytic gas oil were examined by Mandl (2341). The formation of hydroperoxide, alcohols, ketones, acids, and their esters was clearly seen. Infrared spectroscopy was used by Spasov and his coworkers (3451) to structurally evaluate the differences in the thermodiffusive fractions of a gas oil fraction. As part of a study on the characterization of Cia-alkylnaphthalenes, Mayer et al. (2451) obtained 13 of the possible 14 trimethylnaphthalene isomers. Only the 1,2,8-trimethylnaphthalene isomer could not be obtained. The paper contains both the IR and NMR spectra of these isomers. Freeman et al. (1061) used laser excited Raman spectroscopy to study the spectra of di- and tri-substituted acyclic and cyclic compounds containing 1 to 4 methyl groups di-
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rectly attached to ethylenic carbon atoms. They report that the ratio of the intensities of the Raman Bands a t *1375 and *1440 cm-' is dependent on the number of such methyl groups, except for the 2-methylalk-1-enes. The combination of gas chromatography and infrared spectrophotometry is apparently much less popular than the gas chromatography/mass spectrometer combination. Janik (1681) compared the results obtained with a gas density cell with those obtained by an infrared method for the GCIIR analysis of a benzenelcyclohexane mixture. Crooks et al. (661) used an interrrupted gas chromatographic elution technique to provide single component fractions for the IR measuring cell and obtained spectra for 1OO-Kg quantities of organic compounds down to the 1%level. The system was used to separate and identify a mixture of low boiling unsaturated C4 hydrocarbons which could not be completely characterized by gas chromatography and mass spectrometry. Ultraviolet spectrophotometry was used by Heros et al. (1451) to determine pyrene, anthracene, chrysene, benzo[alpyrene, and caronene, which were selectively sublimed from a variety of materials. Breshchenko and his coworkers (391) used UV absorption to determine trace amounts of aromatics in a hydrogenated kerosine. The threshold sensitivities for benzene and naphthalene type hydrocarbons were about 0.005 and 0.002% weight, respectively, with a relative error of &4.5%. Aromatic hydrocarbons were also the subject of a paper by Castex (581) who used UV absorption spectrophotometry and spectrofluorimetry to aid in determining the optimum cut points for hydrocarbon fractions having different degrees of aromaticity. These methods also aided in identifying sulfur containing heterocyclic families. Bamberg (191) reports that the tendency of a sample to form petroleum resins as the concentration of the solution is increased, can be determined by comparing the fluorescence spectra before and after topping. The maximum for the associated molecules occurs a t smaller wave numbers than the maximum for the dispersed ones. Fluorescence spectrometry was used by McKay et al. (2251) to identify aromatic ring systems such as benzocarbazoles, benzo[ghi]perylenes, and coronenes in high boiling petroleum distillates. Similar compounds in petroleum fractions were determined by Sheinerman (3261) by the low temperature fluorescene of the fractions dissolved in Cj-Cl0 normal paraffins. The external heavy atom effect was used by Zanker (3911) who used iodomethane in benzone as the solvent for a number of polycyclic hydrocarbons. Generally, iodomethene quenched the fluorescence, except for rubrene, perylene, %methyl perylene; dibenzo[a,f]perylene, and naphtho[2,3,-6]carbazole or its N-methyl derivative, thus allowing for the determination of these compounds in complex mixtures. Gevantman (1181) surveyed the analytical spectral data sources including all types of spectra for hydrocarbons. Separation Techniques, The analysis of heavy distillates requires the use of complex separation techniques to determine the detailed composition of the sample. Haines et al. (1381) reported a procedure for separating acids, bases, and neutral nitrogen compounds prior to detailed analysis of the distillate fractions. Jewel1 et al. (1731) extended the technique to separate out saturate and aromqic fractions. Latham et al. (2031) discussed the total combined techniques used in the characterization of heavy end distillates. Dooley et al. (841) reported the use of these techniques and the composition of Swan Hills distillate. Coleman et al. (641) reported similar data on Alaskan crude oil heavy distillate. 198R
Duswalt et al. (871) systematically separated and characterized the dinuclear aromatics in the 275 to 295 "C fraction of catalytic gas oil. Chemical Methods. There is a reduced interest in chemical methods of analysis for hydrocarbons, although some techniques are being developed, particularly for olefins. Shukla et al. (3301) used the reaction of N-bromosuccinimide with olefins to determine unsaturation. They report that the method is not applicable to compounds such as maleic acid owing to the presence of electron withdrawing groups adjacent to the double bond. Smits et al. (3371) reacted olefin-containing samples with ozone; an indicator, Organol red BS was used to indicate when ozone adsorption had ceased. Smits et al. (3381) later reacted the methoxy hydroperoxides, formed by ozonolysis of the olefins, with dimethyl sulfide. The methoxy-hydroperoxides were converted into aldehydes and ketones which were then determined by gas chromatography, thus allowing the double bond position to be determined. Rogers (3041) used an enthalpimetric method for determining. He measured the heat evolved during the catalytic hydrogenation with a palladium catalyst. Williams et al. (3781) and Rogers et al. (3051) extended and refined the technique. Rogers et al. (3061) also applied the technology to the microdetermination of allylic and vinylic unsaturation. A coefficient of variati'on was obtained for solutions in the 26- to 184-wM range. Boss et al. (371) used a combination of techniques for the analysis of the oxidation products of n-dodecane. The olefins were determined by mild bromination followed by gas chromatography. The technique was said to be applicable to wide boiling petroleum stocks. Hutzinger et al. (1551) used exhaustive chlorination of aromatic compounds to show that polychlorodibenzofurans were not present in samples of Halowax 1074. Volakova e t al. (3711) used oxidation with chromic acid to determine a variety of C-methyl groups. The yield of acetic acid from 1 C-methyl group was 0.7 to 1.0 mole. Fenske et al. (991) described an apparatus for the analysis of hydrocarbons based on the generation of a stabilized cold flame. The position of the cold flame front can be correlated with the composition of the hydrocarbon sample. Physical Properties. The solubilities of light hydrocarbons in di-2-ethylhexyl sebacate by saturation of a gas-liquid chromatographic column was reported by Carter e t al. (531).The method does not depend on the adherence of the chromatographic process to a particular mathematical model, and is claimed to be generally applicable. The use of nomograph for the calculation of liquefied petroleum gas density was reported by Zander (3901). The nomograph is applicable for mixtures containing 0-4.5 wt YO ethane, 10-40 wt % isobutane, and 10-55 wt % propane. Edwards (881) reported on the prediction of Jet Fuel properties from gas chromatographic data. Gas chromatographic techniques were also used by Brockmeier et al. (411) who determined the thermodynamic properties of polyethylene solutions in n- hexane and isooctane. Leung et al. (2061) also studied polymer solution thermodynamics, and determined the Flory-Huggins interaction parameters a t infinite dilution of C;j to Cg n-alkanes, benzene, and cyclohexane, in polyisobutylene. Calculation of gas chromatographic response factors from physical properties of the solutes were performed by Wojdala et al. (3811). The calculated and experimentally determined factors agreed well. Ioffe et al. (1611) determined the distribution coefficients ( K D )of aromatics in fractions of stabilized catalytic reformate ranging from 60-95 to 150-175 "C. The distribu-
A N A L Y T I C A L CHEMISTRY, VOL. 47, NO. 5. APRIL 1975
tion coefficients were used in the direct dispersometric analysis of reformate and the results compared with those obtained by sulfonation. Ioffe et al. (1601) also developed a nomogram of specific refraction and refractive index which enables the content of naphthenes in the non-aromatic portion of straight run petroleum to be determined. Katsobashvile e t al. ( I 791) measured the physical properties, including viscosity, and the elemental and hydrocarbon-type compositions, of the 350-400 and 400-450 OC fractions from hydrocracking petroleum residue over a cobalt-molybdenum-alumina catalyst after dewaxing and separation of the fractions into five cuts. Six fractions resulting from the molecular distillation of the pentane-deasphalted residuum of Kuwait Crude were investigated by determining their physical properties, aromatic content, number of aromatic and naphthenic rings, and the proportion of condensed rings. The crystallinity of the sub-fractions appears to be directly related to the presence of paraffinic structures either free, or as side chains, to naphthenes and/or aromatics. The separation of liquid hydrocarbons by thermal diffusion was studied by Major (2301, 2311). The most nearly spherical moleculars in the liquid state tend to congregate a t the cool wall and then descend to the bottom part of the thermal diffusion slot. An extensive study of the aromatic fractions of bp 340590 O C was performed by Barabadze and his coworkers (201). Refractive indices, molecular weights, elemental composition, and empirical formulas are reported for 380 eluates from the alumina separation of the 510 "C+ fractions. Miscellaneous. Oehlmann (2671) discussed methods of analysis for petroleum and petroleum products. Howard (1531) discussed the applications of a variety of techniques to the analysis of petroleum middle distillates. Scholze (3171) used the sulfur and vanadium content to determine whether fuel oil sludges were from petroleum fuels or brown coal fuels. Berthold e t al. described the combined use of gas chromatography, NMR, IR, and UV to the structural group analysis of preseparated aromatic concentrates (291)and mineral oil products (301). Bernhard et al. (281) used spectroscopy to analyze hydrocarbon mixtures for their molecular weight and C-ratio after chromatographic separation into aromatics and saturates. The relative proportion of methyl, CH2, CH, and quarternary carbon groups in paraffinic and naphthenic structures was determined by IR. The directly and indirectly substituted methyl and CH2 groups in the aromatic fractions were determined by NMR. Zimina et al. (3941)reviewed applications of gas chromatography and molecular spectroscopy to similar problems. Postnov et al. (2911) reported on the composition of isoparaffinic fractions of kerosine from Mangyshlak petroleums. Ackermann et al. (11) used gas chromatography and infrared spectroscopy to analyze reformates for aromatic compounds. Bryanskaya et al. (481) described the separation and analysis techniques they used to analyze the kerosine fractions of a number of USSR crude oils. D'Arrigo (671) reviewed the analytical methods for the analysis of polycyclic aromatic hydrocarbons in oils and fats. Gilchrist e t al. (1201) used a combination of thin layer chromatography and mass spectrometry for the analysis of polycyclic aromatic hydrocarbons in mineral oil. Pop1 et al. (2891) analyzed pyrolysis oil with particular emphasis on the pyrolysis resins. Kuklinskii e t al. (1921) examined the differences between high boiling complex naphthenes that did and did not form thiourea complexes. Filippov e t al. (1011) also studied high boiling naphthenes. Lopienska
(2151) separated paraffins from asphalt. Detusheva e t al. (721) evaluated methods for determining the purity of high boiling naphthenic-paraffinic hydrocarbons such as white oil. Vamos e t al. (3651) described a complex method for investigating the composition of cosmetic white oils. Warren e t al. (3771) described the isolation and characterization of the bicycloparaffins in the kerosine fraction of the Ponca Crude used in the API Research Project 6. Pozdand nikina e t al. (2931) prepared tri~y~lo[5.2.1.0~~~~]decane tricyc10[4.2.1.1~~9]decane by transannular dehydrocyclization. The compounds are representative of the polycyclic naphthenes found in some crude oil. Yakubson et al. (3841) prepared tricyclo[6.2.1.02~7]undecaneand related compounds by isomerization of adamantene compounds with A1Br3.
Metals in Oils H. A. Braier Gulf Research & Development Co., Pittsburgh, PA
Nuclear Methods. The geochemical significance of 29 trace elements in Iraqi crudes was determined by AlShahristani and Al-Atyia (15)by means of neutron activation analysis with reactor irradiation and gamma-ray spectrometry. Palmai (684 used instrumental neutron activation analysis to study the distribution of vanadiu,m, sodium, manganese, and aluminum in several fractions of Romashkino crudes. Irradiation with reactor-produced thermal neutrons was used by Patek and Sorantin (695) to determine trace elements in crude oils. Eight long-lived radioisotopes were counted after chemical separation while seven short-lived radioisotopes were determined by instrumental analysis. Arroyo and Brune ( 5 J )described a routine neutron activation procedure to determine vanadium in oils and catalysts. From 0.2 to 2000 ppm vanadium have been determined using a 2 X lo9 n/cm2/sec thermal neutron flux and instrumental analysis. A fast neutron generator with a paraffin moderator was used by Blankova et al. (11J) to analyze crudes for vanadium in the 5-45 ppm range. Gibbons e t al. (30J) reported on the simultaneous determination of vanadium and sodium by reactor irradiation and instrumental analysis using a high resolution Ge(Li) detector. Sensitivity limits in distillates and crudes are 0.002and 0.02 ppm for vanadium and 1.0 and 10.0 ppm for sodium, respectively. A direct and non-destructive method using a Cockroft-Walton accelerator was used by Persiani and Shelby (715) for the rapid determination of vanadium and sodium in heating fuel. In a study related to oil-spill identification methods, Filby and Shah (285) used thermal neutron activation analysis to investigate the mode of occurrence of 15 trace elements in crude oils. By using thermal activation analysis, Lukens et al. (565)developed a technique for oil-slick identification. Nearly 300 trace-element patterns were accumulated, by means of which it can be ascertained whether or not two samples are from the same or different oils. Detailed instructions to use this oilslick identification technique are given by Lukens (575). Flame Spectrometric Methods. Organic acids were investigated by Kabanova et al. ( 4 2 4 for their use as a matrix for diluting oil samples as well as solvents for metals used as standards. Propionic acid gave the best results. Westwood (975) described a new sampling method for flame photometry in which oil samples are emulsified with organic detergents so the sample can be diluted with water.
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Korovin and Mashireva (485) presented data on the flame temperatures, relative sensitivities, and reproducibility in laminar and turbulent type burners for flame spectrometry of metals in petroleum products. The determination of antimony in petroleum additives, lubricating oils, and greases was accomplished by Supp (915) by atomic absorption spectrometry. Zinc and barium additives did not interfere. Campbell and Palmer (155) determined from 0.1 to 12.5 ppm of lead in petroleum products by iodine-chloride extraction and atomic absorption analysis with an air-acetylene flame. Gomiscek e t al. (315) described an analytical technique for the atomic absorption determination of several metals in petroleum and petroleum coke. A direct atomic absorption determination of calcium, barium, and zinc in lubricating oils was reported by Guttenberger and Marold (335). These authors used solutions of inorganic salts in dimethyl sulfoxide as standards. Korovin et al. (495) determined traces of sodium in high-ash barium sulfonate additive and in petroleum products using atomic absorption spectrometry and a special burner to produce a nonsmoking flame. Maragnoni et al. (625) studied the effect of metallic interferences in the atomic absorption determination of some metals in aircraft lubricating oils. A survey made by Prazak (745) shows that atomic absorption spectrometry is the best of all spectrometric methods used by various American companies to determine wear metals for engine maintenance purposes. According to Rimmer ( 7 9 4 , atomic absorption has proved itself for lubricating blending control. Although less rapid than emission spectrography, its freedom from matrix effects makes it more versatile. Atomic absorption was used by Ropars (805) for the direct determination of vanadium, sodium, and nickel in heavy fuel oils. Tuzar et al. (925) employed atomic absorption to determine wear metals in used engine oils and barium, calcium, and zinc in additives and lubricants. Vigler and Gaylor (945) reported on the use of atomic absorption for the determination of traces of lead, vanadium, and other metals in petroleum products for environmental purposes. Kashiki et al. (455) described the direct determination of vanadium and nickel in fuel oils by atomic absorption. Samples are diluted with a solution of 4-methyl-2-pentanone, toluene, and methyl alcohol. Yutkevich and Minut (1015) reported on the direct atomic absorption determination of vanadium in heavy fuels. Samples were diluted with isobutyl methyl ketone. From 2 to 42 ppm of nickel was determined by Alder and West (25) in crudes and residual fuel oils by carbon-filament atomic absorption with an unenclosed filament atom reservoir. The use of a carbon-filament reservoir for the determination of 0.01-20 ppm of vanadium in petroleum products was reported by Everett et al. ( 2 6 5 ) .The use of a carbon-rod atomizer for the analysis of lead in petroleum and petroleum products is described by Bratzel and Chakrabarti ( 1 4 5 ) . A detection limit of 2 ppb of magnesium in lubricating oils was achieved by Chuang et al. (195) by atomic absorption spectrometry with the graphite-filament atomizer. Chakrabarti and Hall ( 1 6 4 evaluated the carbon rod atomizer for routine analysis for vanadium in crude oils by atomic absorption spectrometry. A carbon-rod atomizer of the mini-Massmann type was used by Hall et al. ( 3 4 4 to evaluate the routine determination of trace metals by atomic absorption spectrometry. Pate1 and Winefordner (705) reported on the use of graphite-rod atomization and atomic fluorescence for the simultaneous determination of silver and copper in jet-engine oils. Flameless atomic absorption spectrometry with a graphite furnace was used by Prevot and Gente (765) t o determine metallic traces in oils. The sensitivity was better and the precision poorer than 200R
with conventional atomic absorption. Reeves et al. (775)effected a rapid atomic absorption determination of silver and copper in used oils by sequential atomization from a graphite rod. Reeves et al. (785) determined the concentration of seven wear metals in used lubricating oils by atomic absorption with a graphite rod atomizer. Amprimoz ( 3 5 ) analyzed used engine oils by atomic absorption and infrared spectrometry. Data from the two procedures are correlated to detect engine wear. A comparison of atomic absorption and emission spectrometry for the determination of wear metals in normally operated diesel engines was presented by Jackson (405). Origer (675) described a bearing damage detection method for production diesel engines which combines engine test and the determination of silver in oil filters by atomic absorption. X-Ray Fluorescence. Marangoni et al. (615) studied the determination of wear metals in lubricating oil from aircraft motors. Chromium, iron, nickel, tin, and lead were determined with a detection limit better than 1 ppm and good reproducibility a t the 5-ppm level. Lutrario et al. (5951, achieved limits of detection of 0.3 ppm for iron, and 0.2 ppm for nickel and chromium in lubricants by optimizing instrumental parameters. The same authors (585) reported a 0.5-ppm detection limit for copper in lubricants using a chromium target tube operated a t 20-60 kV and 20-60 mA, and a plastic sample holder with an aluminized polyester film window. Fujita and Yamauchi (295) described the determination of up to 3% lead in gear oils. Iron does not interfere but results must be corrected for copper absorption. A procedure to determine vanadium (0.050.5%) in heavy distillate fuels by X-ray fluorescence after concentration by distillation was reported by Boyle (125). Furnished data support the validity and consistency of this analytical approach. Solazzi (875) described a liquid sample holder for analyzing metal constituents in lube oils by vacuum X-ray fluorescence. Emission Spectrometry. Biktimirova and Mashireva ( 9 5 ) studied the increase in detection limits of metals in petroleum products. By the addition of specific additives, these authors were able to increase several times the intensities of vanadium, nickel, chromium, calcium, molybdenum, and iron lines. Kuznetzova et al. (505) reported on the optimal nitric acid treatment conditions for resinous and asphaltic crude oil fractions for the spectrographic determination of vanadium, nickel, copper, manganese, lead, and titanium. This procedure is compared with methods using sulfuric acid. A simple, rapid, and reproducible spectrographic procedure for metals in hydrocarbons is described by Lakatos ( 5 4 5 ) .The sample, diluted with chloroform, is carried to a high voltage spark gap by means of a rotating disk electrode. Shmulyakovskii et al. (84J) determined traces of copper, lead, and arsenic in catalytic reforming feedstocks by taking the spectra of electrodes on which the samples had been evaporated. Traces of barium strontium, and boron in crude oil ash were determined by Petho ( 7 2 4 , using small amounts of synthetic silicatedolomite-type spectrographic aid materials. Beloglazova et al. ( 8 5 ) established that the presence of iron and aluminum up to 3% and of nickel up to 0.02% do not interfere on the determination of traces of boron in petroleum bitumens. Nickel, vanadium, copper, and iron were determined in oil products by Munteanu et al. (635). Samples were dried, ashed, and dissolved, and the solution was evaporated on carbon electrodes previously impregnated with polystyrene. By using an improved arc generator and a thin walled carbon electrode, Polkanov and Sotnikov (735) analyzed lubricating oils for metals with high reproducibility. McElfresh and Parsons (605) developed a spectrographic meth-
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5. APRIL 1975
od for the determination of wear metals in oils by means of a plasma jet dc arc using a direct force feeding approach to overcome sampling problems. Barr and Larson ( 7 5 ) used emission spectrometric data for ten wear metals in aircraft lubricants as an aid to evaluate engine condition. The procedure can be adapted to a computerized system. Esenwein (255) described experimental conditions for the investigation of eleven trace metals in lubricants using a directreading spectrometer. Some refinements and improvements in a computerized direct-reader system were reported by Coulter et al. ( 2 0 5 ) .The system is used for wear metals in lubricating oils but it can be applied to other types of spectrographic analysis. The use of a direct-reading emission spectrograph with a rotating graphite disc was described by Woods (1005).Samples as small as 0.5 ml can be used since the sample floats on deionized water contained in a small plastic cup. Hauptmann and Jager (365) compared rotating disc and rotating platform techniques for the spectral analysis of metals and phosphorus in mineral oils. Advantages and disadvantages of each technique for the analysis of certain elements are discussed. The determination of iron, chromium, and copper in oils and lubricants with the use of a magnesium oxide collector was presented by Soroka et al. (885). The use of this collector shortens ashing time and decreases ash losses. A semiquantitative spectrographic method for the rapid determination of eighteen elements in petroleum products without the use of reference standards was described by Soroka et al. ( 8 9 5 ) . Wolff (995) described a 3-hour spectrographic procedure to determine calcium, barium, zirconium, iron, lead, nickel, vanadium, and copper in ash from spent engine oils. The effect of barium on the accuracy of analysis of wear metals in lubricants was discussed by Sokolov and Tishchenko ( 8 6 5 ) . Samples from aircraft turbine engines taken every three days over a period of one year were spectrographically analyzed for eight wear metals by Jantzen ( 4 1 5 ) . The author discusses results and the effect of fresh oil additions. Lakatos (535) in a study on the matrix effects of hydrocarbons on the determination of metals, showed that spectral line intensity was inversely proportional to the log of the heat of vaporization of the solution. Hanafi and Al-Zewel (35J) reported on a spectrographic procedure to determine aluminum, iron, nickel, and vanadium in boiler fly ash from residual fuel oil. Kyuregyan (515) described a microspectrographic procedure for metals in petroleum products. The procedure is based on special sample preparation and electrode pretreatment. Another microspectrographic procedure based on special sample preparation and electrode pretreatment was presented by Klemm (465). Greenfield and Smith (32J) determined traces of aluminum, chromium, and copper in microsamples of engine oil (up to 100 ppm) by using regular spectrographic equipment and plasma-torch excitation. The advantages of spectrographic analysis of lubricating oils to detect incipient engine wear were discussed and illustrated with case histories by Drost (245). By monitoring wear metals in lubricating oils, the U S . Air Force (SOAP program) saves from $13 to $15 million a year. The use of NBS certified standard materials in this program is discussed in reference ( 6 5 5 ) . Miscellaneous. A review on the determination of metallic elements in crude oils by means of spectroanalytical methods was offered by Lakatos (525). Braier ( 1 3 4 discussed several instrumental techniques for the analysis of trace metals in fuel oils. A survey on the trace metal content of various distillate fuels was conducted by Ward ( 9 5 4 . von Lehmden et al. (555) presented an interlaboratory comparison of selected analytical techniques for the analysis of twenty-eight elements in coal, fly ash, fuel oil,
gasoline, and their related emission products. Nelson (645) indicated how to estimate the metal content of a vacuum or atmospheric distillate residue by knowing the content of some metals and the gravity of the crude. A rapid complexometric method for lead in lubricating oil was described by Banerjee and Dutta ( 6 5 ) .The lead naphthenate was separated from the oil by mercaptoacetate extraction and titrated with EDTA. Zinc and other metals contained in lubricating oil additives were determined by Fernandez (275) by direct titration with EDTA using high-frequency endpoint indication. Engine breaking-in was monitored by Sosnina et al. ( 9 0 5 ) ,by means of complexometric determination of iron in the used oil. Wilson and Marczewski (985) reported on the direct complexometric determination of metals in used lubricating oils and additives by automated nonaqueous potentiometric titration. Kabrt and Moravek ( 4 3 J ) , described the simultaneous determination of barium, zinc, calcium, and phosphorus in mixtures of lubricating oil additives. The procedure combines a gravimetric determination of barium and a complexometric determination of the other elements. Diskina et al. (235) determined lead in oils as sulfate, and carbon and hydrogen simultaneously by conventional microanalysis. Anand et al. ( 4 5 ) determined zinc in lubricants and additive concentrates by ashing, solvent extraction, and colorimetric finish with dithizone. A procedure was described by Norwitz and Galan (665) for the spectrophotometric determination of antimony in sebacate-base lubricants. Color is developed by the iodide method. A colorimetric procedure to determine vanadium in ashes of petroleum fractions was reported by Ugarkovic and Legin (935).Color development is based on the chelation of vanadium with 1-(2 pyridy1azo)2-naphthol (PAN). Preis (75J) describes a quick procedure for the determination of vanadium in petroleum products without incineration of the sample, which is decomposed by acids and finished colorimetrically with 3,3'-dimethylnaphthidine. Karbainov et al. (445) studied different acid mixtures and optimized conditions for the wet ashing of petroleum products prior to photometric determination of traces of vanadium, nickel, and cobalt. A simple colorimetric method, suitable for semiskilled operators was applied by Jackson and Dalzell (395) to determine low ppm of iron and copper in used lubricating oils. Hulanicki and Karwowska (385) determined vanadium in petroleum coke by burning the sample and dissolving the ash in acids. The acid solution is then suitable for photometric determination with N- benzoyl-N-phenylhydroxylamineor for coulometric titration with electrolytically generated ferrous ion. Ruessel ( 8 2 4 separated chromium, iron, and phosphorus compounds in used oils by liquid chromatography and determined these elements by wet analysis. This author concludes that, apparently, iron and chromium are dissolved from the engine steel by phosphorus-containing additives. A method to study wear particles in used lubricating oils was presented by Seifert ( 8 3 5 ) .It is based on the distribution of magnetic wear particles from an oil sample when poured on a microscope slide under the influence of a magnetic field (ferrogram). Westcott and Seifert (965) indicated that discrepancies found in the iron content of used oils when determined by reading ferrograms and by emission spectrometry are largely due to the facts that not all iron is present as magnetic particles and that iron in large particles is not detected by emission spectrometry. Experimental electron spin resonance data accumulated by Dickson et al. (215) confirms the usefulness of this technique to characterize vanadium(1V) compounds in petroleum. Electron spin resonance and visible spectroscopy were used by Dickson and Petrakis (225) to characterize five vanadium-con-
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taining fractions from crude petroleum. Kolganova and Berman (475) studied the distribution of nickel and vanadium in petroleums and rccks by determining nickel, vanadium, and their porphyrin complexes. Methods for porphyrin separation are given. A method for the rapid determination of vanadium in oils in the ppm range was reported by Hetman (375). The sample is burned in a high pressure oxygen bomb and pentavalent vanadium is coulometrically titrated with a constant current automatic coulometer. A polarographic microdetermination of cobalt, nickel, and antimony in organic compounds and petroleum was described by Bishara et al. (105).Iron, nickel, and cobalt, as carbonyls, were determined in natural gas by Chlebovsky (185). The carbonyls were absorbed and oxidized in concentrated nitric acid with a polarographic finish. In a work by Roschig et al. ( 8 1 4 on the distribution of lead in oil-refining products, this element was determined by anodic stripping voltametry, complexometry, and polarography. Copper, cadmium, and lead were simultaneously determined by Sinko et al. (855) in petroleum and petroleum coke by means of anodic stripping voltametry. The application of anodic stripping voltametry to the determination of traces of copper in petroleum is mentioned by Chernova e t al. (175).
Nonmetal Elements and Compounds W. E. Haines and D. R. Latham Laramie Energy Research Center, Bureau of Mines, U.S. Department of the Interior, Laramie, WY
Sulfur. The determination of total sulfur was the subject of the majority of the sulfur-related papers. Miyazawa and Tayama (98.K)presented a review of the oxygenhydrogen combustion method for the determination of sulfur in organic compounds, especially petroleum. Bannuscher (IOK) prepared a review with 139 references on the determination of carbon, hydrogen, nitrogen, sulfur, chlorine, and phosphorous and other chemical tests common to the petroleum industry. Shigeta and Imai (127K) reported on the analysis of standard samples prepared by the Japan Petroleum Institute; samples containing 0.5, 1.0, and 2.0% sulfur were prepared by blending light and heavy petroleum distillates. Total sulfur is most commonly determined by oxidizing the sample and determining the resulting sulfur dioxide. Modifications in both the oxidation step and the finishing technique continue to appear. Scroggins (123K) reported a collaborative study on the oxygen flask combustion with a variety of finishes; differences in precision and accuracy were small. An oxygen flask combustion method was used by Nuti and Bacci (106K) who suggested the addition of known amounts of sulfate (as sulfuric acid) to the solution for titration when micro-samples were used; the solution is adjusted to pH 3-4, Thoron I is added, and the solution is titrated with barium perchlorate in isopropanol. Kuriya et al. ( 8 0 K )titrated the sulfur dioxide from an oxygen-hydrogen flame combustion potentiometrically, using ion-selective lead electrodes; interference of the electrodes by hydrogen peroxide was removed by destroying excess hydrogen peroxide with a catalase. Avgushevich et al. ( 7 K ) burned samples a t 850-900 O C in oxygen, absorbed the obides in hydrogen peroxide, and, after evaporating the water, determined the sulfur dioxide photometrically with 202R
Chlorophosphonazo 111-Ba2+ reagent. Sulfur in fuel oil was determined by Helling ( 5 4 K ) by oxidizing in pure oxygen and passing the gas to an automatic titration vessel containing a mixture of hydrogen chloride, potassium iodide, and starch; potassium iodate is added automatically (photoelectric cell) to maintain the blue color which is bleached by the incoming sulfur dioxide. Determination of total sulfur by chemical oxidation was reported in three papers. Eliseeva et al. (38K) reported that complete oxidation takes place when samples are heated with hydrogen peroxide in the presence of alkali; sulfate was determined by titration with a solution of barium chloride, using Orthanil K as the indicator. Sulfur in fuel oil was determined by Lautenbacher and Baker (83K) by oxidizing to sulfate with 30% hydrogen peroxide and absorbing in a solution containing a measured excess of barium; the barium sulfate was separated by centrifugation, and the remaining barium was measured by atomic absorption spectroscopy. Banateanu et ai. ( 9 K ) oxidized petroleum samples with manganese dioxide, added barium acetate in acetic acid, and titrated the excess sulfate ions with perchloric acid in the presence of neofuchsine. Determination of total sulfur by reducing the sulfur to hydrogen sulfide was suggested by several authors. Volodina and Martynova (151K, 152K) determined sulfur in organic compounds containing halogens by pyrolysis in a stream of ammonia followed by potentiometric determination of sulfide ion; chlorine, bromine, and iodine are retained in the tube as ammonium halides, and addition of boric acid eliminates the negative effect of fluoride ions; for thiophenes, reduction was carried out in the presence of an aluminosilicate catalyst. Kimbell (71K) patented an apparatus for continuous determination of total sulfur in liquid hydrocarbons which is based on pyrolysis a t 700 "C to convert the sample to smaller molecules and by hydrogenation to convert the sulfur into hydrogen sulfide for measurement. For the automatic determination of ppm sulfur, Slanina et al. (129K) heated the sample a t 1050 O C in a hydrogen stream over quartz wool to give hydrogen sulfide which was absorbed in a potassium hydroxide-hydroxylamine solution and immediately titrated with lead nitrate a t an ion-selective electrode in an automatic titrator. Honarkhah (57K) determined trace amounts of sulfur in light, nonolefinic hydrocarbons by reacting the sample with activated Raney nickel and then adding acid to liberate hydrogen sulfide which is absorbed in Borax solution and titrated iodometrically. The combined determination of traces of nitrogen and sulfur compounds reported by Diarova et al. (32K)involves the reduction of a sample over Raney nickel, the addition of hydrochloric acid, determination of the hydrogen sulfide evolved, and titration of the remaining nonvolatile nitrogen base compounds. Svajgl et al. (143K) evaluated oxidation and reduction methods for the determination of trace amounts of sulfur in petroleum distillates and reported that both methods were suitable in fractions boiling up to 200 "C, but for higher boiling fractions only the oxidative method is useful. Determination of total sulfur by coulometric titration of products from sample oxidation or reduction received the attention of several workers. Braier et al. ( 1 9 K ) compared the results of the oxidative and reductive mode of coulometric analysis in the 1-100 ppm level using standard solutions of model compounds (molecular weights less than 200) and concluded that the reductive mode was highly superior. T o improve the conversion of sulfur to sulfur dioxide, Dixon (33K) modified the combustion procedure by burning the sample in oxygen and carrying the products of combustion in a stream of helium to a cell in which sulfur
ANALYTICAL C H E M I S T R Y , - V O L . 47, N O . 5 , APRIL 1975
dioxide is titrated with electrogenerated iodine. Cedergren ( 2 7 K ) described an oxidative coulometric trace determination in which he achieved about 99% conversion to sulfur dioxide by vaporization and pyrolysis of the sample in nitrogen a t 400 "C, combustion in a mixture of nitrogen and oxygen a t 700 "C, and then equilibration a t 1000 "C after dilution of the product mixture with more nitrogen. A method by Carter ( 2 5 K ) pyrolyzes the sample a t 450 "C in nitrogen and then burns the products in oxygen a t 750-800 "C; a simple inexpensive constant-current coulometer was described. Hoshino (58K)reported an automatic apparatus for the determination of sulfur in petroleum; the apparatus is a modification of a sulfur analyzer for iron and steel, which is based on high-temperature combustion by highfrequency induction heating and coulometric titration. In a coulometric method for the simultaneous determination of sulfur and chlorine by Hetman (56K),a few milligrams of sample are burned in oxygen a t 1250 "C and the gases are absorbed in hydrogen peroxide; one aliquot is titrated with hydroxyl ions to determine total acids, the other aliquot is titrated with silver ions to determine chlorine; sulfur is obtained by difference. In an attempt to overcome problems in determinations in the sub-ppm range, Killer (70K) delayed the microcoulometric titration of the petroleum combustion products until interfering phenomena in the cell had ceased by using the "standby" position of the amplifier to the Dohrmann microcoulometer. Miscellaneous methods for the determination of total sulfur include atomic absorption, proton activation analysis, X-ray, and the use of the Salet phenomenon. Kirkbright et al. (73K, 7 4 K ) reported the direct determination of sulfur in oils by atomic absorption spectrometry using an inert gas-shielded nitrous oxide/acetylene flame; direct aspiration of samples, diluted with isobutyl methyl ketone, into this premixed flame permits rapid determination of their sulfur content a t 180.7 nm. A nondestructive protonactivation method was applied by Burton et al. ( 2 4 K ) ; crude oils with sulfur contents of 0.06 to 1.23% were studied using the 32S(p,cu)29P reaction; the detection limit, when using a 1-second irradiation with 18-MeV protons in air, was about 100 ppm. A proton-activation analysis method suggested by Thomas and Schweikert (145K) involves irradiation for 1 second to effect the reaction 32S(p,n)32Cl; the activation curve for this reaction is given for proton energies up to 25.5 MeV; the sensitivity is estimated to be about 50 fig per square cm. A "nondispersive" X-ray fluorescence spectrometer was developed by the Stazione Sperimentale per i Combustibili and the University of Rome (117K);the apparatus consists of a sample excitation system (a radioactive tritium-zirconium source), a gas proportional indicator, and a unit that registers impulses. Kobayashi et al. ( 7 5 K ) determined sulfur in heavy oils by fluorescent X-ray spectrometry; samples are solidified with paraffin to eliminate the effect of bubbles, and sulfur contents are determined by measuring the K radiation. Russ (120K) discussed the need to eliminate background and interfering peaks before obtaining quantitative results with X-ray fluorescence spectrometry using energy-dispersive analysis of X-rays; examples of the suggested methods are applied to determining sulfur in oil. A patent by Alessio e t al. ( 5 K ) describes an analyzer for sulfur in hydrocarbon fluid, in which fluorescent X-rays are produced from the 241Am-Rh reflection mode radioactive source and passed through the hydrocarbon sample; a signal proportional to the sulfur content is generated. Measurement of sulfur content in hydrocarbons with a radioisotope digital-indicationtype sulfur analyzer is suggested by Inoue et al. (60K). Veillon and Park (148K) used the Salet phenomenon in the
determination of sulfur and phosphorus; a burner was designed to produce the Salet emission spectra from sulfur with a maximum a t 384.0 nm; the method was used for determining sulfur from 0.0044 ppm to 2.1% in petroleum liquids. Gaseous sulfur compounds were studied by several workers. Kremer and Spicer ( 7 6 K ) accomplished a gas chromatographic separation of hydrogen sulfide, carbonyl sulfide, and other sulfur compounds using 30% tritolyl phosphate on Chromosorb P support in a two-column system with gas-flow reversal. In a study of the relative retention volumes of various stationary phases on brick, Kudasheva and Yurkevich ( 7 7 K ) showed that mixtures of carbon dioxide, ethanethiol, carbon disulfide, and sulfur dioxide can be separated on Apiezon L; hydrogen sulfide and carbonyl sulfide can be separated with squalane. Ronkainen et al. (118K) used Triton X-305 on Chromosorb G with flame photometric detection for the gas chromatographic analysis of carbon dioxide, carbonyl sulfide, hydrogen sulfide, ethanethiol, and methyl sulfide. Hems and Adams ( 5 5 K ) monitored sulfur dioxide concentrations in the 0.02 to 10% range by automated gas chromatography using 20% dinonyl phthalate on Embacel. In a study of the gas chromatographic stationary phases for low-temperature concentration of refinery gases such as carbonyl sulfide, carbon disulfide, thiophene, methanethiol, and ethanethiol, Lulova and Timofeeva ( 8 7 K ) found that squalane or dimethyl sulfolane worked best. Fritz and Chang ( 4 2 K )used macroporous resins for sorption and separation of gases, including sulfur dioxide and hydrogen sulfide, by gas chromatography. Staszewski and Zygmunt (136K) determined hydrogen sulfide and thiol sulfur in gases by titration of the gases absorbed in sodium hydroxide solution with 0-(hydroxymercuri)benzoic acid in the presence of dithiofluorescein as an indicator; one sample is passed through a cadmium chloride pre-adsorber to remove the hydrogen sulfide, so that thiols only are titrated; the other sample is passed through sodium hydroxide only, to give a titration of hydrogen sulfide plus thiol. Maurice ( 9 3 K ) determined traces of thiols in light hydrocarbons spectrophotometrically; the sample was shaken in a high-pressure device with 5,5'-dithiobis(2nitrobenzoic acid) to form a yellow mercaptide; photometric measurement a t 412 nm allows detection of 0.02 ppm of thiols. A method for determining hydrogen sulfide in liquid petroleum products was patented by Marsh ( 9 2 K ) ; the sample is added to a toluene-isopropanol mixture buffered a t p H 7 and potentiometrically titrated with cadmium chloride using a silver/sulfide-glass electrode system. Shokarev, et al. ( I 2 8 K ) reported the analysis of sulfur dioxide, carbon dioxide, hydrogen sulfide, carbon disulfide, carbonyl sulfide, and their mixtures, using infrared adsorption spectroscopy with the IKS-14 spectrophotometer with standard 300-ml cuvets and a 200-mm optical track; a reaction between sulfur dioxide and hydrogen sulfide was not observed. A spectrophotometric determination of thiophene, carbonyl sulfide, and carbon disulfide reported by Novikov et al. (104K) is based on treatment with ethanolic diethylamine to form the dithiocarbamates; extinction measurements are made a t 230, 235, and 290 nm. Waszak (155K) designed a galvanic cell for the determination of sulfur compounds in various gases by catalytic conversion of the sulfur to sulfur dioxide or hydrogen sulfide which react with electrolytically generated chloride; sulfur is then calculated from the decrease in chlorine concentration. Sulfur in liquid hydrocarbon gases was determined by Gulyaeva et al. (51K) by flameless combustion a t 900 "C in a quartz tube and air current; the products were extracted with hydrogen peroxide and the sulfur oxides were deter-
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mined by titration or nephelometry. A survey by Seitz and Neary (124K) included the application of chemiluminescence to sulfur-containing air pollutants and sulfur in petroleum products. The determination or identification of thiols was the subject of six papers. Svajgl and Holle (141K, 142K) developed a method for the determination of thiols and elemental sulfur by coulometric argentometric titration which uses coulometrically generated silver and biamperometric end-point indication with silver/silver sulfide electrodes a t 300 mV. The determination of thiols described by Verma and Bose (150K) involved titration in nonaqueous solution with lead tetraacetate; the end point was detected either potentiometrically at a platinum electrode or by using quinalizarin indicator; iodide, bromide, sulfide, and thiocarbonyl compounds interfered seriously. Peter and Rosset (113K) compared potentiometric titration by means of a single-crystal silver/sulfide electrode with titration with the conventional silverhilver sulfide electrode; the response of the single crystal is not Nernstian, but either electrode system is useful for determination of thiols and hydrogen sulfide in petroleum products. Specjal (133K) identified 11 thiols in gasoline from Rybaki crude oil by gas chromatography of thiols that had been extracted with a methanol-potassium hydroxide-water solution containing 1% cresolates. A method for removing aromatic and acid hydrocarbons impurities from thiols of petroleum origin, patented by Obolentsev e t al. ( I I O K ) , involves treatment with aqueous sodium hydroxide, separation of the aqueous thiol-containing layer, and extraction of this layer with dimethyl sulfoxide or ethylene glycol to remove the impurities. Using a combined procedure of ordinary and differential spectrophotometry, Shekdar and Venkatachalam (126K) estimated dissolved sulfur and butanethiol in heptane solution on the basis of their ultraviolet absorption a t 300 mp and a t 225 and 238 mp, respectively; hydrogen sulfide, thiols, thiophenes, and aromatic hydrocarbons do not interfere in the sulfur determination, but some sulfides and polysulfides interfere strongly. The organosulfur compounds-predominately sulfides and thiophenes-in various Russian petroleums were studied by several groups in the USSR using various approaches which are not always clear in the translated abstracts. Rubinshtein e t al. (119K) studied the structural-group composition of hydrocarbons and sulfur compounds in a distillate from a Tuimaza petroleum by a "proposed difference method" and found that the sulfur compounds were predominately derivatives of diphenylene sulfide, dinaphthylene sulfide, and phenylene naphthylene sulfide, with some naphthenic-aromatic derivatives of thiophene. Sulfur compounds in the Uzbekistan petroleums were studied by Abdurakhmanov ( I K , 2 K ) by separation on KSM silica gel to produce a naphthenic-paraffinic and an aromatic-sulfur-containing fraction; the latter fraction was repeatedly chromatographed on alumina and then vacuum distilled to produce fractions for further study. Mazitova et al. (94K) separated the sulfur compounds from a Romashkino diesel fuel by two-stage oxidation; the mild oxidation product was mainly thiacyclanes; the more severe oxidation product was distilled to produce eight fractions-early fractions were benzothiophene dioxide and the last fraction contained three-ring compounds. Vyakhirev et al. ( 1 5 4 K ) studied the material boiling up to 200 "C in a Romashkino petroleum by chromatographing distillate fractions on a variety of liquid phases; by examining the relative-retention volumes, they identified five thiols and six sulfides in the below-120 "C portion and five thiols, four aliphatic sulfides, three thiophene derivatives, and seven thiophane de204R
e
rivatives in the 120-200 O C portion. The composition of narrow fractions of sulfides obtained from kerosene-gas oil fractions of Arlan petroleum was studied by Nikitina e t al. (102K) who found that the light fractions contained mainly monocyclic; the middle ones, mono- and bicyclic; and the high ones, tricyclic sulfides. Obolentsev e t al. (108K) used adsorption chromatography on silica gel to produce a sulfur concentrate (7.2% S) and a desulfurized distillate (0.1% S) from a kerosine distillate (0.7% S).Obolentsev e t al. (107K) identified 14 thiols, 17 alkyl sulfides, and 8 cyclic sulfides in the organic sulfur compounds recovered from gasoline distillates by chromatography, by mercuric acetate treatment, and by extraction with sodium aminoethoxide in anhydrous ethylenediamine; identification procedures included fractional distillation, gas-liquid chromatography, hydrogenolysis on Raney nickel, and mass spectrometry. Abramovich e t al. ( 3 K ) used gas-liquid chromatography to investigate the selectivity of 28 solvents in the separation of cyclic and aliphatic sulfides; the data obtained suggested phenol as the extractive solvent. Several Russian studies depended upon sulfuric acid extraction of the sulfur compounds. Chertkov e t al. (30K) extracted the sulfur compounds from a 150-325 O C fraction of an Arlan petroleum by sequential treatments with 86,91, 92, and 93% sulfuric acid; 86-91% acid extracted 68% of the sulfur and 95% of the sulfides present; this extract was chromatographed on alumina to give thiaalkanes, alkylthiacyclanes, thiacyclanes, and thiaalkylbenzenes and some oxygen-containing compounds formed in the oxidation step. A 189-350 "C distillate from the Arlan petroleum was studied by Obolentsev e t al. (109K) who extracted with 86 and 91% sulfuric acid a t a 1 : l O acid:distillate volume ratio and treated the extracts with aqueous mercuric acetate solutions; the compounds separated were mainly substituted thianaphthenes. Galeeva e t al. ( 4 4 K ) fractionally distilled a sulfurous concentrate isolated from a kerosine distillate and then separated the fractions on silica gel to obtain thiophenes, sulfides, and hydrocarbons. Bondarenko e t al. (16K) suggested extraction a t 20 "C with a double solvent consisting of 85.9% sulfuric acid and benzene; the combined solvents gave extracts that contained greater amounts of total and sulfide sulfur than those from sulfuric acid alone. Miscellaneous studies of sulfides included a comparison of the determination of aliphatic sulfides in lubricatingcooling liquids by a polarographic method with a platinum microelectrode and by an ultraviolet method a t 308 mp by Soroka and Kotlov (131K);the UV method was slightly more sensitive. Kamidate e t al. (65K) achieved quantitative extraction of dimethyl, diethyl, dipropyl, or dibutyl sulfide from heptane or pentane into an aqueous phase with cupric bromide/magnesium bromide additives. Galeeva e t al. ( 4 5 K ) found that 3-hexylthiophene, dibutyl sulfide, and 2-hexylthiophane were sharply separated by chromatography a t 20 "C with KSM silica gel adsorbent which had been roasted a t 300 "C for 6 hours. Lerman e t al. ( 8 4 K ) prepared a group of alkylcyclohexyl and dicyclohexyl sulfides in 94-99% purity and determined their cryoscopic constants and infrared spectra. Gas chromatography was used by several workers to study sulfur compounds. George e t al. ( 4 6 K ) found that lithium chloride-Chromosorb W gave efficient separations of sulfur compounds and was especially useful for investigation of high-boiling materials because of its heat stability. Sawatzky et al. (121K) subjected narrow-boiling fractions of Athabasca bitumen to gas chromatography; first, on column packings with polar organic stationary phases to separate the major portion of the sulfur-free material from the sulfur-containing material; the latter was separated
ANALYTICAL CHEMISTRY. VOL. 47, NO. 5 , APRIL 1975
into several classes that were trapped and further chromatographed on salt packings; the effluent from the salt column was passed into a mass spectrometer for characterization. The determination of trace amounts of organic sulfur compounds by gas chromatography with flame photometric detection was reported by Perry and Carter (112K) who studied absorptive losses and the quenching effect of coincidentally eluted nonsulfur compounds on the emission intensity; P,p-oxydipropionitrile was the most selective stationary phase. Sugiyama et al. (140K) studied the emission intensity of diatomic sulfur in a flame photometric detector and concluded that the relationship between the emission intensity and the amount of sulfur-containing compounds varies considerably with the flow rate of air and hydrogen in the burner. Golovnya and Arsen'ev (47K) developed a gas chromatographic analysis for homologous series of thiols, sulfides, and disulfides which depends upon the rectilinear relationship between the retention index on various stationary phases and the number of carbon atoms, and between the index and boiling point; optimum selectivity was obtained with PEG 1000, PEG 20,000, Apiezon M, and Triton X-305 on a column of Chromosorb N with nitrogen as carrier gas. A selective sulfur detector for gas chromatography was suggested by Blasius and Lohde (15K)who hydrogenated the gas chromatographic effluent to produce hydrogen sulfide which was detected on a thin-layer plate containing lead acetate; the lead sulfide zones were then evaluated optically by measurement of the degree of reflectance at 565 nm; the detection limit was 5 ng of sulfur. An on-line elemental reaction analyzer developed by Liebman et al. (85K) combines gas chromatography and reaction microchemistry for the determination of empirical formulas, functional groups, and heteroatoms such as sulfur, halogens, oxygen, and nitrogen. Hydrodesulfurization was used to identify individual sulfur compounds, particularly sulfides. The method depends on desulfurization and subsequent identification of the hydrocarbon fragments. Thompson and Rall (146K) described a microhydrogenation apparatus and procedure applicable to many samples as small as 0.000005 ml; the system was used to identify most of the 175 sulfur compounds found in petroleum in a Bureau of Mines study. Gusinskaya and Beiko ( 5 2 K ) catalytically desulfurized in a microreactor between two chromatographs; the platinum catalyst, AP-56 retained its activity after many runs. Several studies of sulfides and thiophenes involved the use of mass spectrometry. Castex et al. (26K) used a combination of mass spectrometry and gas chromatography with selective flame photometric detection to obtain a profile of the thiophenes in 50 "C distillate cuts of crude oils and rock extracts; a comparison of the results provided a correlation between the chromatogram profile and the chemical composition. Yusupova et al. (157K) studied sulfide concentrates from medium and heavy fractions of Tadzhik petroleums with the MKh-1303 mass spectrometer and found that the chief components were thiamonocyclanes with 10 carbons and thiabicyclanes with 11 carbons; dialkyl sulfides, cycloalkyl sulfides, cyclic mono-, di-, tri-, and tetrasulfides, and thiaindans were also present. Using model aromatic hydrocarbons and sulfur compounds, Brodskii et al. (21K) developed equations relating mass spectral data with molecular structure. Several papers appeared concerning the distribution of sulfur and sulfur types in petroleum and petroleum products. Specjal (134K) prepared narrow-boiling fractions (up to 300") of Rybaki crude oil and analyzed each fraction to determine total and free sulfur, hydrogen sulfide, thiols, sulfides, and disulfides; the most characteristic feature of
the oil was the high content of thiols. The distribution of sulfur compounds in petroleum and petroleum products of western Kazakhstan was studied by Lobanova and Kotova (86K);in the majority of fields, the sulfur content was related to the age of the enclosing rocks. Shcherbina et al. (125K) found that free sulfur, thiols, disulfides, and alkyl sulfides accounted for 3, 20, 15, and 43%, respectively, of the total sulfur in a straight-run gasoline; thiol decreased with boiling point, while other types increased. Stemberger (139K) investigated the sulfur compounds in straight-run and visbreaking gas oil from the Iraq/Kirkuk region before and after desulfurization; the compound types were concentrated and separated chromatographically and then characterized by determination of their physical and chemical constants and by their infrared and ultraviolet spectra; the study showed that hydrodesulfurization removes the sulfides more readily than it removes the thiophenes. An infrared spectroscopic study of sulfur-containing compounds in petroleums, bitumens, and in their fractions by Proskuryakova and Gromova (116K) showed that thiophenes and sulfoxides appeared in the bicyclic aromatic hydrocarbon fractions and that sulfones and substituted thiophenes appeared in the polycyclic aromatic fractions. Drushel (35K) characterized residual and hydro-treated products by liquid-solid chromatography on alumina and by asphaltene adsorption on the catalyst and showed that the sulfur content and molecular weight distribution of the asphaltenes remaining in the product are essentially constant, regardless of the overall level of residuum hydrodesulfurization. The distribution of total sulfur in distillates and residua from 43 crude oils was presented by McKinney (90K);data showed that sulfur content usually increases with boiling point and that the sulfur content of the residue can be estimated if the gravity and sulfur content of the crude are known. Efimova et al. (36K) used model compounds to demonstrate a potentiometric method for determining sulfur types; a silver chloride electrode was used for the direct determination of thiols and a mixture of thiols and free sulfur; disulfides were determined via reduction to thiols and sulfides by titration with potassium iodate. Sulfonic acids and sulfonates were the object of four studies. Kupfer and Kuenzler (79K) separated petroleum sulfonates on a silica gel column by elution, first with dichloromethane, and then with ethanol-dichloromethane; the sulfonates in the eluates were identified and determined by ultraviolet and infrared spectrophotometry. In a method useful for finished lubricants, Brewer (20K) removed sulfonates from the oil by converting them to the sodium salt, which was separated from the oil by chromatography on silica; the sulfonates were dissolved in chloroform and determined by a two-phase titration with a quaternary ammonium salt in the presence of dilute sulfuric acid, using a mixture of Dimidium Bromide and Disulphine Blue as indicator. Sulfonic acids in acid sludges were determined by Velitskaya and Kondrashova (149K)by a method based on the ability of the bound sulfuric acid in the sludge to react with Methylene Blue and form colored complexes that are soluble in chloroform; free sulfuric acid did not interfere. Ali and Laurence ( 6 K ) separated primary and secondary alkane monosulfonic acids from di- and polysulfonic acids over a CS to CZOcarbon number range by columnpartition chromatography; a moist cellulose column retained the di- and polyacids while the monoacids were eluted with n-butanol/petroleum ether; the monoacids thus separated were titrated with standard alkali. Oxygen. The determination of water by a variety of methods was the subject of several studies. Kudryavtseva
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et al. (78K) determined traces of water by gas chromatography, using the porous polymer Polisorb-L; a sensitivity of lo-% and an analysis time of 12-15 minutes were claimed. The reliability of using the porous polymer material, Porapak, for water and alcohol analyses was investigated by Gough and Simpson (48K); the authors found that water was adsorbed by this material and that careful control of experimental conditions was required to obtain accurate results. Gvozdovich et al. ( 5 3 K ) used a Teflon column packed with Chromosorb 101 to determine trace amounts of water; the results were in good agreement with those obtained by the Karl Fischer method. A modification of the Karl Fischer reagent for determining water was developed by Delmonte ( 3 1 K ) ;the r'eagent contains a sulfoxide or an organic nitride as the reducing agent, a base compound that contains a pyridine skeleton, and iodine. The determination of water by a radiofrequency absorption method is discussed by Benzar and Bakhmatov ( 1 3 K ) ;the basic apparatus is described and results from seven petroleum products are presented. Fexa et al. ( 4 1 K ) developed a water analysis method that is based on the evaluation of changes in the conductance of the sample that are caused by changes in water content. Measurement of the temperature increase due to the addition of acid to the sample is the basis of a rapid method developed by Mahn and Cosentino ( 9 1 K ) for the determination of the water content of emulsion samples. Ershova (39K) described an improved method for the determination of water in which calcium hydride is reacted with the sample; a shorter analysis time than the original method is claimed. Meloan and Bunting (95K) determined ppb quantities of water in benzene or carbon tetrachloride; the reagent, cobalt piazselenole chloride, is decomposed by the water in the sample and the liberated piazselenole determined photometrically. An infrared spectrophotometric method reported by Alekseeva and Yudovich ( 4 K ) to determine water dissolved in various hydrocarbons has a sensitivity range from 3 to 15 ppm. A method for determining traces of dissolved oxygen, using the absorption of oxygen in an ammoniacal solution of cuprous chloride was described by Gulyaeva et al. (50K); the amount of absorbed oxygen is determined by measuring the optical density of the solution and comparing it with a calibrated standard curve. Direct determination of the elemental oxygen content of petroleum-refining products on a gas chromatographic analyzer is reported by Pokrovskii et al. (114K). A commercial automatic elemental analyzer for determining micro quantities of oxygen, as well as carbon, hydrogen, and nitrogen, in petroleum was investigated by Smith et al. (130K);the analyzer gave results comparable to those of conventional methods a t oxygen levels of 0.2 to 1.0 wt 96. Merz (96K) developed methods for elemental analysis of oxygen, nitrogen, carbon, and hydrogen that permit the use of a computer for automation of the analyses as well as for processing the results. The simultaneous microdetermination of oxygen and nitrogen in organic compounds was described by Ubik (147K);the sample is pyrolyzed in a hydrogen atmosphere a t 1050 OC over layers of nickel and platinized carbon; the carbon monoxide and nitrogen are separated on a Porapak Q chromatographic column and determined with a katharometer. Determination of alcohols was the subject of three papers. Ivanenko et al. (61K) determined traces of C1 to Cq alcohols in naphtha by water extraction, followed by GC analysis of the extract; results were obtained for samples containing 4 to 100 ppm of alcohols. GC analysis of synthetic C ~ to O CIS aliphatic alcohols was reported by Nichikova et al. ( I O I K ) ,using a column of Dinochrome-P with 206R
polymethylphenylsiloxane fluid PFMS-4 as the stationary phase. Boss (17K)identified the alcohol and ketone isomers produced by the pyrolysis of n-paraffins by comparison of their gas chromatograms and mass spectra with similar data on known compounds. Organic peroxides produced by oxidation of hydrocarbons were determined by a gas chromatographic procedure developed by Cerveny et al. (28K);the results were consistent with those obtained by iodometric titration. Scoggins (122K) found that methyl ketones and aldehydes through Cg and most branched-chain carbonyl compounds through C7 can be quantitatively determined using the 2,4-dinitrophenylhydrazine extraction method. Infrared spectroscopy was used by Spedding and Noel (135K) to analyze for carbonyl compounds in lacquers removed from piston surfaces. The isomer composition of alkylphenols with chains of 10 to 20 carbon atoms was determined by a mass spectrometric method developed by Brodskii et al. ( 2 3 K ) ; the method is based on characteristic relationships in the highvoltage fragment patterns of alkylphenols. A new spectrophotometric method for the determination of 4,4'-methylenebis(2,6-di-tert-buty1)phenol in mineral oil was reported by Bozicevic and Fuks (18K);the analysis is made in an ultraviolet spectrophotometer in ethanol. Zakupra and Chernetskaya (158K) developed an apparatus for the rapid analysis of high-molecular-weight alkylphenols; a glass column with a spirally roughened interior surface was used for the separation of the phenols. Weak and very weak acids were determined in heavy petroleum fractions and asphalts by Nakajima and Tanobe (99K) by potentiometric titration with tetramethylammonium hydroxide in isopropanol-pyridine solution; the method is especially useful for determining very weak acids, such as alkylphenols. In the thermometric titration method for weak acids, the use of acrylonitrile as sample solvent results in a more sensitive end-point detection than when acetone is used (Greenhow 49K). A rapid ion exchange chromatographic method was developed by Bidlingmeyer and Bergmann ( 1 4 K ) for determining traces of p-toluic acid and 4-carboxybenzaldehyde in terephthalic acid. Analysis of carboxylic acid was reported in two papers by Russian workers; the acids were converted to their methyl esters that were analyzed by gas chromatography. Nikitina et al. (103K) analyzed the methyl esters of branched C11 to C15 carboxylic acids using a copper capillary column with polyphenyl ether as the liquid phase. The method of Chernyak (29K) involved the correlation of the number of carbon atoms with the retention times of the methyl esters. A chromatographic separation scheme for characterizing high-boiling petroleum distillates described by Jewel1 et al. (62K) involved, in part, the removal of the acid compounds with an anion exchange resin, Amberlyst A-29; the acids were removed from the resin by successive elution with benzene, methanol, and methanol-carbon dioxide; acid fractions were prepared from several oils. McKay et al. ( 8 9 K ) used adsorption and gel permeation chromatography to separate acid fractions obtained from high-boiling petroleum distillates; infrared spectroscopy was used to characterize the acids according to compound type. Teeter and Seifert (144K) reviewed the spectral techniques they used to identify over 40 classes of carboxylic acids in a California petroleum. The neutral oxygen compounds separated from an Estonian shale oil by distillation and adsorption chromatography were investigated by Kasberg ( 6 6 K ) ;about 13%of the 66 to 200 "C fraction was neutral oxygen compounds; these were hydrogenated on a platinum catalyst to the corre-
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
sponding saturated hydrocarbons and analyzed by gas chromatography. Nelson (100K) discussed the refining problems caused by oxygen in straight-run and cracked products; the oxygen contents of several heavy gas oils, Bunker C fuel oils, and heavy catalytic oils are reported. Nitrogen. Total nitrogen methods were improved by several researchers. A method by Merz ( 9 7 K ) for rapid determination of nitrogen used fully automated equipment; pure oxygen is used to burn the sample, the combustion gases are passed over copper oxide and copper into a nitrometer where the nitrogen gas is determined volumetrically. The reliability of the Dohrmann microcoulometric titrating system was evaluated by Kajikawa et al. ( 6 3 K ) ;the correct combustion-tube inlet temperature for the sample was a critical parameter for obtaining accurate results. Baldulina and Fedoseev ( 8 K )determined total nitrogen by pyrolysis of the sample in the presence of cupric oxide and copper; the resulting nitrogen is measured with a microeudiometer. Samples containing about 0.1% total nitrogen were first extracted with 96% sulfuric acid before determination of the nitrogen by the Kjeldahl method; the preliminary extraction ensures rapid decomposition during the acid digestion step; reproducible results were obtained with a relative error of 1%(Kiricenkova and Vesely ( 7 2 K ) ) .Bannuscher (IOK) reviewed methods for determining total nitrogen. Improvements in the techniques and apparatus for the simultaneous determination of total nitrogen, as well as other elements (carbon, hydrogen, sulfur, and/or oxygen) were reported in several papers. Pella and Colombo (111K) modified the combustion/gas chromatography method to permit the analysis of small samples (0.1 to 3 mg) for carbon, hydrogen, and nitrogen; instantaneous combustion of the sample is followed by catalytic oxidation of the gases over chromic oxide and contact of the gases with silvertreated copper at 640 “C; the apparatus was automated and the data were presented as printed integration values. Lapteva et al. (82K) developed a dual-column apparatus for determining nitrogen, carbon, and hydrogen; nitrogen is determined in a carbon dioxide atmosphere in one combustion tube and carbon and hydrogen in an oxygen atmosphere in the other tube. A commercial elemental analyzer for determining micro quantitites of nitrogen, oxygen, carbon, and hydrogen was investigated by Smith et al. (130K); the analyzer gave results comparable to those of conventional methods a t nitrogen levels of 0.05 to 0.1%. Merz (96K) developed methods for elemental analysis of nitrogen, oxygen, carbon, and hydrogen that permit the use of a computer for automation of the analyses as well as for processing the results. The simultaneous microdetermination of nitrogen and oxygen was described by Ubik (147K);the sample is pyrolyzed in a hydrogen atmosphere at 1050 OC over layers of nickel and platinized carbon; the resulting carbon monoxide and nitrogen are separated on a Poropak Q chromatographic column and measured with a katharometer. A method by Diarova et al. (32K) for the combined determination of nitrogen and elemental sulfur involves reduction of the sample with Raney nickel, addition of hydrochloric acid, determination of the resulting hydrogen sulfide, and potentiometric titration of remaining nitrogen bases. Basic nitrogen in a jet fuel was determined by Lyashenko et al. (88K) using a colorimetric method; the sample was dissolved in a mixture of chloroform and acetic acid and titrated with 0.02N perchloric acid using Crystal Violet as indicator; a t the end point, the color turns from violet to sky blue. Frycka and Pospisil (43K) used a gas chromatog-
raphy column coated with orthophosphoric acid to remove nitrogen bases (pyridine, 2,3-dimethylaniline) from coal tar liquids; the authors were not interested in the quantitative amount of bases present but just in removing them. A mass spectrometric method for analyzing basic nitrogen compounds in petroleum was reported by Brodskii et the compound-type composition was determined al. (22K); by combining the data obtained from low-voltage spectra (parent peaks) with data from high-voltage spectra (fragment peaks); the combined method was used to analyze bases from a resin-asphaltene fraction. Khmel’nitskii et al. (67K) developed a mass spectrometric method for the quantitative determination of 12 groups of nitrogen bases ranging from C,Hz,-sN to CnH2,,-21N and from CnHzn-gNS to C,H2n-13NSa The composition of basic nitrogen compounds was the subject of several papers. Stekhun et al. (138K) investigated the nitrogen bases in a naphtha fraction obtained by hydrocracking; aniline, alkyl anilines, alkyl pyridines, and quinoline were identified by gas chromatography and infrared spectroscopy. In the study of a similar fraction from a different crude, Ben’kovskii et al. (11K) identified aniline, 0-,m-, and p-methylaniline, and 2,4-dimethyl-, and 2,4,6-trimethylpyridines; the ratio of 0-,m-, and p-methylanilines was 100/10/1. A second study by Ben’kovskii et al. (12K) was made on a gasoline fraction obtained by hydrocracking, using gas chromatography, ultraviolet, infrared, and mass spectroscopy; several alkylaniline and alkylpyridine compounds were identified. A concentrate of basic nitrogen compounds prepared by chemical treatment and ion exchange chromatography was found by Numanov et al. (105K) to contain 21% alkylpyridines, 32% alkylquinolines, and 47% alkylbenzoquinolines. Hypta and Kedzierska (59K)determined the basic nitrogen content of several fractions from Romashkino oil by potentiometric titration. Potentiometric titration was used by Egiazarov et al. ( 3 7 K ) to investigate the bases in two oils; the amounts of strong and weak bases present in these oils were determined. The basic nitrogen compounds present in a shale oil light distillate were characterized by Poulson et al. (115K); the bases were predominately pyridine-type compounds with lesser amounts of pyrrolic types, cyclic amides, anilides, and unidentified nonpyrrolic types. A chromatographic separation scheme for characterizing high-boiling petroleum distillates described by Jewel1 et al. (62K) involved, in part, the removal of the basic nitrogen compounds using a cation exchange resin, Amberlyst 15; the bases were removed from the resin by successive elution with benzene, methanol, and methanol-isopropylamine solvents; base fractions were prepared from several crude oils. Several miscellaneous studies involving nitrogen were reported. The relationship between the color stability of a kerosine fraction and nitrogen content was studied by Kajikawa and Kawaguchi (64K). The color stability was improved by reducing the nitrogen content to less than 0.1 ppm. Determination of nitrogen dioxide in a mixture with ethane, propane, and butane by reaction gas chromatography was reported by Doering et al. (34K); the sample is reacted with a triphenylphosphate-coated column to give nitrogen oxide, which is measured with a thermal conductivity detector. Lakatos et al. (81K) determined the porphyrin content of Hungarian crude oils by adsorption spectroscopy; several solvents (ethanol, dimethylformamide, acetonitrile, and a mixture of acetic and bromic acids) were investigated for their ability to extract porphyrins from the oil; acetonitrile was found to give the best results. The refining problems caused by nitrogen in crude oils was dis-
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cussed by Nelson (100K);nitrogen contents are presented for crude oils, distillates, and residua from California, Venezuela, and the Middle East. Halogens. A method for the determination of halogens in organic substances by Volodina et al. (153K)is based on heating the sample in a current of ammonia a t 850 O C followed by potentiometric titration of the mixed ammonium halides with silver nitrate in a solvent of water, acetone, and acetic acid, using silver and calomel electrodes. Kidani et al. (69K) decomposed the halogen compounds with sodium, treated with silver nitrate, removed the silver chloride precipitate, and measured the excess silver by atomic absorption spectrophotometry. An on-line elemental reaction analyzer reported by Liebman et al. (85K) combines gas chromatography and reaction microchemistry for the determination of empirical formulas, functional groups, and heteroatoms such as sulfur, halogens, oxygen, or nitrogen. The determination of chlorine in additives suggested by Sosnina and Krasnova (132K) is based on oxidation of the chlorine-containing additive in an oxygen atomosphere followed by titration of chlorine with mercuric nitrate using diphenyl carbazone as indicator. Felsen and Gilbert (40K) analyzed hydraulic fluids for chlorine-containing contaminants by volatilizing the relatively low-boiling contaminant from the nonvolatile fluid and leading the vapors to an evacuated infrared gas cell; after equilibration an IR spectrum is run and compared with a calibration curve which is made with measured amounts of standard contaminants in the base fluid. Khudyakova et al. (68K) examined the standard method (GOST 2401-62) used to determine the salt content in thoroughly desalted petroleums and found that it was within the precision limit of 1 mg salt per liter. The spectral determination of small amounts of iodine in lubricating oil by Stefanenko and Novikova (137K) is based on precipitation of the iodine as silver iodide and ashing the precipitate for spectral analysis; iodine can be determined in concentrations of 0.008 to 0.15%. For the determination of fluorine in petroleum and petroleum process catalysts, Wilson and Marczewski (156K) developed procedures for preparing analytical solutions from crude oils, residua, petroleum products, and process catalysts; after treatment with sodium biphenyl or alkaline fusion, and aqueous extraction, the fluoride was measured directly in aqueous extracts with Wilson’s lanthanum trichloride electrode; lower detection limits were 0.1 ppm in crudes and residue, 0.01 ppm in distillates, and 2 ppm in catalysts.
Analytical and Process Instrumentation J. W. Loveland and C. N. White Sun Oil Co., Newtown Square, PA
In this year’s review, we have added a few additional sections not contained in the 1973 review. One section deals with the area of pollution and the other covers new or improved instrumental techniques and equipment which have general applicability and replaces our previous section on applications. The other sub-sections are directed a t elemental analysis, individual and type compound analysis, and physical property methods. Because of the frequent reference to familiar techniques and terminology we are using abbreviations to aid the reader in his perusal of the text. Abbreviations recommended 208R
by Chemical Abstracts will be used and not itemized here. Other abbreviations are as follows: AA-atomic absorption; IR-infrared; UV-ultraviolet; MS-mass spectrometry; GC-, LC-, TLC-, gas, liquid, and thin layer chromatography, respectively; XRA-, XRD-, XRF-, X-ray absorption, diffraction, and fluorescence, respectively; NMR-nuclear magnetic resonance; TC-thermal conductivity (detector); FID-flame ionization detector; std devstandard deviation; vis.-viscosity; psig-pounds per square inch gage; 0.d.-, id.--, outer and inner diameter; in.-inch; and HC-hydrocarbon(s). In preparing this review, the authors were impressed with the tremendous activity in several areas. The computerization of GCs in both laboratory and process environments was most evident to reduce manpower requirements while providing more accurate and timely information. Computers were more fully utilized with MS and XRF. The need for improved control of all refinery operations increased the development of more selective and sensitive techniques for trace elemental and specific compound analysis. Particular emphasis was observed for trace detection of metals in oils for catalyst protection and in water for pollution control. Some highly sophisticated laboratory techniques have been automated for on-line detection of components such as lead and sulfur in liquid HC streams. Whereas previous reviews covered review papers in the introduction, this year we will include only those of broad scope. Other review articles of a specific nature will be included in the appropriate sections. The following are recommended for a general reading and cover a broad spectrum of techniques andlor applications. Mayer et al. (157L) reviewed the development of instrumental methods since 1947 for the analysis of gasoline components with emphasis on the use of MS and GC. Camin and Raymond (40L) discussed in a lengthy review (81 references) the development of chromatography in the petroleum industry both as a bulk separation process or as an analytical method. The various forms of chromatography, i.e., gas-liquid, liquid-liquid, gas-solid, and liquidsolid are discussed in detail as they relate to the characterization and analysis of various refinery streams. The role of LC and GLC in the petrochemical industry was reviewed by Keulemans (123L). The analysis of gases, gasolines, and other petroleum products was presented by Lulova (143L). Martin (1555) discussed TLC as an approach to fast, quantitative analysis for petroleum industry applications. Trace amounts of diols in fatty alcohols and the relative amount of total disulfonates in petroleum derived olefin sulfonate samples can be determined. A combination of techniques for molecular structure determination was elaborated by West et al. (229L). New developments in MS, IR, Raman and NMR spectroscopy and XRD, together with elemental analyses are used. Zimina et al. (238L) reviewed spectroscopic IR, UV, MS, NMR, and atomic methods as applied to petroleum products, demulsifiers, alcohols, and various additives. Jaeger et al. (116L) reviewed methods for determining solid foreign materials in mineral oils including light scattering, microscopy, conductivity, silting index and other methods. Summaries of papers and discussions held in London were reported by Douglas on the recognition of crude oils by capillary GC (61L) and the analysis of gases and HC mixtures using various recent techniques (62L). Spencer (204L) by considering various aspects of production planning and process operating techniques determined the desirability of installing analyzers. The evalua-
ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
tion when properly coordinated avoids the danger of overor under-instrumentation. Van der Hiejde et al. (219L)discussed the rapidly growing need for mass production of analytical data with emphasis on computer processing of the data. Various spectroscopic analyses are also reviewed. Sokolin et al. (202L) outlined the differences between laboratory and process GC functions and equipment. Process applications for the control of C1-C4 separations and Cs aromatic separations and for the production of C7-Cg fatty acids were discussed. Gaur (88L) has discussed the relative advantages of manual and automatic control. Instruments for the measurement of temp., pressure, flow rate, and liquid level are compared according to the degree of accuracy and range desired. Controllers of various types are discussed including the use of programmed timers for activating controllers at predetermined cycles. A review with 87 references was made by Schiele (192%) covering various measuring technologies including the following: Liquid level, gas and liquid flow, vis., etc; pollution instrumentation for air and water; temp. and other thermal properties of gases, liquids, and solids. Eroshkina (69L) et al. studied refining units and results from different analyses of product quality to determine the possibility of minimizing the number of analyzers and sampling points. The atmospheric-vacuum distillation of petroleum requires the following: end point for gasoline; flash point and end point for white spirits; flash point, viscometer (or pour point) and colorimeter for diesel fuel; flash point for the mazut stream; and viscometer and colorimeter for wax-distillate.
ELEMENTAL ANALYSIS Laboratory Analyses. Beck et al. (22L) analyzed several hundred samples of oil shale and shale oil using the semiautomated multiple Fisher Assay, mineral C02, precision C-H and gas analysis with synthetic and standard samples to develop useful correlations among the tests. Ebel (67L) used an electronic desk-calculator with a CHN analyzer to calibrate the ultramicro-balance, control the weighing of the sample, start the combustion, integrate the peak areas, and provide an alpha-numeric printout. Stoffel (207L) used the new Erba CHNO analyzer for more than 300 CHN determinations and found std devs of
