ANALYTICAL CHEMISTRY, VOL. 51, NO. 5, APRIL 1979
separation of mercury from environmental samples. Lower limits of detection were given for mercury in air, water, soil, rocks, flour, milk, sawdust, oil, and biological material. May and Presley ( 4 2 4 used y-ray activation to determine chromium and iron in crude oil. Sciuti (574 discussed portable instrumentation for neutron activation, neutron transmission, and X-ray fluorescence with an application of nondestructive analysis of paintings, silver coins, minerals, and oils. X-Ray Fluorescence Spectrometry. Energy dispersive X-ray fluorescence was used by Kubo and Bernthal (284to analyze NRS fuel oil for vanadium, iron, nickel, and molybdenum; and shale oil for iron, nickel, zinc, arsenic, and selenium. Spiked solutions were used for calibration. I t also enabled Yousif and AI-Shahristani ( 7 3 4 to determine sulfur and vanadium in crude oil. They claimed rapid simultaneous analyses with no significant effect of sulfur on the vanadium count rates. Rare earths in misch metal and steel were reported by Alota and Bartoli ( 2 J . T h e samples were oxidized, mixed with lithiiim borate -lithium carbonate flux, and cast in homogeneous buttons. A direct method was also described. Levinson and DePablo (354 reported elements heavier than iron, in particular thorium, niobium, tantalum, and tungsten, with lower limits of detection in the 2C-50 ppm range. Plesch (514 discussed the inherent errors in X-ray spectrometry and estimated them by simulation of standards. He also (525) used standard addition and standard-sample mixing procedures to suppress matrix effects. Barium and zinc were reported in crude oil. Krishnan ( 2 7 4 claimed analyses of samples in any matrix with standards in any convenient form by normalization involving corrections for scattering from the sample cell. Results were reported for zinc, iron, and lead in petroleum using solid or liquid standards. He recommended the addition of glycerol to avoid radiation damage to samples of tetraethyllead in gasoline. He also mentioned a technique for sulfur and chloride without a need for helium atmosphere. New methods for the analysis of lead, vanadium, sulfur, phosphorus, and chloride were reviewed by Kajikawa ( 2 2 4 . Emission Spectroscopy. Wear metals in jet lubricating oils were detected by Grampurohit and Rao ( 1 5 4 using dc arc emission spectrometry. The sample, mixed with gallium oxide, was charred and ashed. A lithium-graphite buffer provided smooth burning and recoveries of 75-122% were obtained for silver, aluminum, chromium, copper, iron, molybdenum, nickel, lead, tin, and titanium. Kapoor ( 2 4 4 reported results for cobalt and molybdenum in aluminumbased catalysts with the sample suspended in motor oil base stock and analyzed by rotating disk. Dutta and Guha (115) detailed a rapid, accurate means of estimating the vanadium content of fuel. They mixed the sample ash with copper oxide and graphite powder. Vanadium and nickel were studied by Katchenkov (25.4 to indicate the genetic relationship of petroleum-bearing rocks. Vanadium-nickel ratios were also compiled by Zul’fugarly and Babaev ( 7 5 4 as they analyzed for trace elements in Bahar Sea and Peschanyi deposits. Ohls ( 4 9 4 used rotrode spectroscopy in a carbon dioxide atmosphere and inductively coupled plasma to determine elements in oils. Detection limits were comparable to those obtained by pressed electrodes. One hundred references on the use of hollow-cathodedischarge tubes were reviewed by Krasil’shchik (264. Mosesco e t al. (455, 4 6 4 used atomic emission to determine sodium in gasoline, kerosene, and fuel oils. They described ashing and dilution techniques using sodium sulfonate for standardization. Electron Spin Resonance. Yamada et al. ( 7 1 4 investigated vanadium porphyrin chelates in Gach Saran residue and Nasirov et al. (47J) determined vanadium porphyrin complexes in various petroleums. Yamada and Sanada ( 7 0 4 followed the structure of vanadium compounds during heat treatment of a Gach Saran residuum and Athabasca tar sand bitumen. Quantitative results on quadrivalent vanadium were determined in distillation residues by Nikishenko et al. ( 4 8 4 . Results at the 0 . 5 5 - ~ glevel were in good agreement with those of atomic absorption or X-ray fluorescence. Miscellaneous. Vanadium in petroleum was determined by Sosnina and Rarsukova ( 6 3 4 using a colorimetric finish. Funk and Gomez ( 2 3 4 also used visible spectrometry to determine vanadium in toluene. Long-time centrifugation at
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high acceleration enabled Marek et al. (394 to concentrate vanadium and nickel in crude oil. The distribution of vanadium and nickel porphyrins in rocks and petroleum was studied by Vinnikovskii et al. ( 6 8 4 using a photometric technique. Sebor et al. (594 separated vanadium and nickel porphyrins in crude oil by gel chromatography. Skostakovskii et al. ( 6 2 4 complexed the vanadium porphyrins with metal halides, regenerated in water, and extracted with chloroform. Serebrennikova et al. ( 6 0 4 used thin-layer chromatography and mass spectrography to identify two main types of vanadylporphyrins in petroleum. The mass spectra of metastable ions of synthetic and petroleum vanadylporphyrins were compared by Suboch et al. ( 6 4 4 . Anipenko et al. (34 described a method of solvent extraction, removal of pigmented impurities, and spectrometric analysis to study the nickel and vanadium porphyrin complexes in crudes. Yotsuyanagi et al., ( 7 2 4 extracted the ternary complex of nickel with 4-(2-pyridylazo)resorcinol and benzyldimethyltetradecyl ammonium chloride into chloroform. The addition of EDTA before extraction reduced metal ion interference. Interference from cobalt was masked by 3-methylglyoxime. High pressure liquid chromatography and atomic absorption were combined by Botre et al. ( 6 4 to determine the alkyllead compounds in gasoline. Shome et al. (614 used amperometric titration to detect lead in gasoline. They found that aluminum, zinc, arsenic, tin, fluoride, and cyanide do not interfere but iron, manganese, and copper need to be masked. Ratovskaya et al. ( 5 4 4 used a similar method for iron and vanadium in petroleum cokes. Fouad and .4min (124reported a new method for lead in gasoline and lube oils where the lead is extracted by nitric acid plus potassium chlorate and titrated with EDTA using xylenol orange indicator. The procedure is claimed to be fast and in good agreement with atomic absorption and ASTM D 526. A spectrophotometric technique enabled Hulanicki and Karwowska (184to determine iron, vanadium, copper, and lead in petrochemicals. The structural group composition of organosulfur compounds in petroleum were studied by Parfenova et al. (504 using mass spectrometry, paramagnetic resonance, and infrared spectroscopy. Sulfur compounds were also studied by Certkov et al. ( 9 4 by adsorption percolation with activated fine-spherical aluminosilicate. Techniques for isolation and characterization of sulfur compounds were developed by Jewel1 and Swansiger ( 2 0 4 . They obtained pure sulfur compounds and separated them by charge transfer and gradient elution chromatography. Goderdzishvili (24-Aformed sulfur photolysis products from the metal-containing sulfur compounds of petroleum products by irradiation with ultraviolet light. An improved Wickbold combustion technique was used by Kunkel (294to determine trace chlorine, arsenic, selenium, calcium, cadmium, lead, and zinc in various organic materials. Copper in gasoline was detected by Mori et al. ( 4 4 4 by chelation with o-hydroxyquinolphthalein and spectrophotometric measurement of absorbance a t 565 nm. Ugarkovic and Legin (664found that dry-transformation was more accurate and reproducible than wet oxidation and that burning time influenced accuracy in the determinations of sodium, potassium, and calcium in diesel and heavy fuel oil. Turina and Turina ( 6 5 4 detected lead from 0.002 and 0.1 ppm by thin-layer chromatography. Interference from sulfate ions was removed with barium chloride. A review of techniques for analysis of antimony, arsenic, beryllium. cadmium, chromium, cobalt. lead, manganese, mercury. molybdenum, nickel, vanadium, and selenium in trace amounts was presented by Davis et al. ( 1 0 4 .
Nonmetal Elements and Compounds W. E. Haines and D. R. Latham Lararnie Energy Technology Center, Lararnie Wyoming ~
Sulfur. Methods for the determination of total sulfur were the subject of many papers. The English (13K)and French (76K) versions of European Standard E N 41 (determination of the sulfur content of petroleum products by the Wickhold combustion method) have been published as BS 5379/EN 41 and N F T 60-142, respectively. Ehrenberger ( 4 1 K ) published
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a review of the technical status of the development, experiences, and guidelines for the use of the Wickbold apparatus. A study of the determination of sulfur in heavy oil by Takano (162K) showed a good correlation between two combustion methods (JIS K 2263 and JIS K 2541) and a poorer correlation between combustion methods and a radioisotopic method. Hlavnicka (69K)improved the combustion apparatus for the determination of halogens and sulfur by adding a ring chamber between the hydrogen-oxygen burner and the silica combustion tube. A method and apparatus for sulfur analysis patented by Mansfield (109K) involves catalytically combusting the sample in an oxygen atmosphere, reacting the sulfur oxides with pyridine in methanol and water, and titrating the pyridine solution amperometrically. Kolobielski (95K) evaluated the oxygen flask combustion technique for determining phosphorus, sulfur, and chlorine in military lubricating oils. For the determination of total sulfur in naphthas, Fernandez et al. (45K) suggested that the sample be vaporized in carbon dioxide, burned in oxygen, the combustion products absorbed in hydrogen peroxide solution, and the sulfate formed titrated in aqueous ethanol with barium perchlorate using a high frequency conductometric titrator. Sulfur is one of the seven elements measured in a microanalysis patented by Grob and Rulon (62K); the products of catalytic combustion in an oxygen atmosphere are carried with oxygen carrier gas to a heated equilibrium zone in which conditions are maintained to optimize the formation of sulfur dioxide which is then separated from the other combustion products by gas chromatography. White (I 72F) improved the combustion microcoulometric method by injecting the sample into a k2.5 oxygen-helium mixture at 700 "C to achieve nearly complete conversion of sulfur to sulfur dioxide. Cassidy (I7K)developed a method of determining elemental sulfur in process water which is based on the selective interaction of sulfur and Poragel; down to 1 ng of sulfur can be detected by spectrophotometry of the eluate at 254 nm. Improvement of the finishing techniques for the combustion method was the subject of several papers. In a modified microcoulometric titration method for sulfur dioxide by van de Laarse (101K), an aqueous solution of the combustion products is injected into a boiling hydrogen iodide/water/ hypophosphite mixture to form sulfate and then sulfur dioxide/hydrogen sulfide mixture which is recombusted. A spectrophotometric titration of sulfate suggested by Burgasser e t al. (16K) involves titrating with barium perchlorate using Thorin as the indicator and monitoring the color change with a probe colorimeter. Hozumi et al. (73K)titrated a buffered acetone solution of the combustion products with barium chloride using NAS 11-18 glass electrodes for end-point detection. For microcoulometric titration of sulfur in samples containing large amounts of chlorine, Cedergren (20K) suggests diluting the combustion-product stream with carbon monoxide at 1300 K, thus keeping the oxygen partial pressure small and converting interfering chlorine compounds into hydrogen chloride which does not interfere with the coulometric titration of the sulfur oxides. The Chromatic S apparatus described by Ito e t al. (79K)determines sulfur in heavy oils by combusting with a metal firing agent and oxiziding the products in hydrogen peroxide; the sulfuric acid formed is electrolyzed with measured pulses of current until the p H returns to the initial value. Clay et al. (26K)determined the total sulfur in gasoline by injecting the sample into a mixing device at 170 "C, carrying it into a hydrogen-air flame with nitrogen, and examining the products with a flame-photometric detector. Many methods fo+ the determination of total sulfur involve hydrogenation to produce hydrogen sulfide which is then measured. Drushel(38K) determined sulfur at the 1-ppm level in light petroleum fractions by noncatalytic hydrogenolysis a t high temperature to form hydrogen sulfide which was monitored with a Houston Atlas Analyzer; nitrogen and halogen compounds do not interfere. A procedure for the determination of sulfur described by Sagdullaeva and Shamsiev (152K)involves hydrogenative degradation of sulfur compounds to hydrogen sulfide followed by adsorption of the hydrogen sulfide in an alkali solution and titration with a dilute mercury acetate solution. Mazor ( I l O K ) hydropyrolyzed a sample and passed the pyrolysis products with nitrogen carrier gas saturated with water vapor through a platinum catalyst bed a t 800 to 1000 "C; the resulting hydrogen sulfide Pndlor sulfur dioxide gases are introduced into an iodine
solution which oxidizes hydrogen sulfide to sulfur and sulfur dioxide to sulfate; the excess iodine is titrated with sodium thiosulfate. Alder e t al. ( 4 K ) suggested a method in which the sample is charred with sodium metal in a test tube, plunged into water, boiled, and acidified; the liberated hydrogen sulfide is swept into a hydrogen-argon cool flame for measurement of the sulfur emission at 384 nm. Equilibrium studies of sulfur, carbon, oxygen, nitrogen, and hydrogen species under the conditions of the reductive sulfur method were made by Cedergren and Sunden (21K). "Sulfur in Petroleum Products by Nondispersive X-Ray Fluorescence Spectrometry" is the title of a new standard developed by the Institute of Petroleum ( 7 7 K ) ;the method involves the use of low energy X-ray emissions from radioactive iron-55 for the determination of sulfur in naphthas, distillates, fuel oils, residues, lubricant stocks, unleaded gasolines, and blended components; metals and halides interfere. A fluorescent X-ray sulfur analyzer, patented by Oda and Badono (127K), includes a source for irradiating the sample with X rays or y rays, a radiation detector and first and second analyzer/measuring devices which select and measure only X-ray fluorescent pulses or Compton scattered rays, respectively, from the detector. Yasuda and Kakiyama ( I 73K) used a conventional X-ray fluorescence spectrometer and a portable instrument with a n iron-55 source for the determination of sulfur in pitch. Two types of radioisotopic sulfur analyzers were tested by Shinozaki (157K)with regard to their accuracy and reproducibility for the measurement of sulfur in heavy oil. Teller (I63K)described a radioisotope immersion probe for continuous or discrete measurements of sulfur and lead; the probe incorporates an americium-241 source, a PTFE-coated beryllium window through which the source radiation passes into the sample, a molybdenum reflector positioned behind the sample, a scintillator to discriminate against unwanted y rays, a photomultiplier, and an amplifier. The Autosulfurmeter described by Ito et al. (79K) for the determination of sulfur in heavy oils uses americium-241 as the energy source and measures the y-ray adsorption by sulfur. Gosset et al. ( 5 8 K ) determined sulfur, nitrogen, fluorine, and lead by y-photon and charged particle activation; the method depends on rapid mineralization of the sample after irradiation according to the Parr-Wurtzschmitt process; nitrogen and sulfur are determined by proton activation. Krishnan (96K)suggested a method of matrix correction in the analysis of petroleum products with solid and aqueous standards by X-ray fluorescence and, in addition, suggested that the use of cotton wads wrapped in polyester film in place of the titanium liquid cells extends the use of X-ray analysis to low-atomic-number elements such as sulfur and chlorine. The development or improvement of sulfur-specific detectors for gas chromatography concerned several investigators. Doehler et al. (33K)reviewed the application of flame photometric detectors and suggested suitable gas chromatographic conditions for analyzing gas, crude benzene, and tar from coal pyrolysis; sensitivity values for 15 sulfur compounds are given. Johansen (27K) used a flame photometric detector with high-resolution, glass, open-tube columns for the analysis of sulfur compounds in petroleum products. An apparatus and method patented by Colin and Herouard (28K) involves passing the effluent from the gas chromatograph through a combustion chamber to produce sulfur oxides which are then introduced into a flame photometric detector. Ruman (151K) used a flame photometric detector to determine microquantities of individual sulfur compounds in light hydrocarbons and suggested that the sensitivity of the detector could be increased by doping the carrier gas with a suitable sulfur background. Franc and Pour (49K)developed a method for the continuous determination of the carbon/sulfur ratio of the effluents from a gas chromatograph; effluents are hydrogenated in a stream of hydrogen over platinum gauze to produce methane, hydrogen sulfide, ammonia, and water; the ammonia and water are adsorbed before the first detector which thus records the amount of methane and hydrogen sulfide; hydrogen sulfide is then removed so that the second detector records the amount of methane. A gas chromatographic system that is selective for sulfur and nitrogen compounds, patented by Fraim (47K),involves atomizing the gas chromatographic effluent into an oxygen-rich atmosphere a t 900-1150 "C and measuring the resultant nitrogen and
ANALYTICAL CHEMISTRY, VOL. 51, NO. 5, APRIL 1979
sulfur oxides with selective (chemiluminescent or fluorescent) detectors. Albaugh and Query (3K) modified the detector system in a previously reported chromatographic method for following changes in carbon and sulfur distribution during desulfurization by incorporating an instrument that converts the sample into carbon dioxide and then into methane which is determined by a flame ionization detector; the sulfur is measured with a microcoulometer in place of the ionization detector. Patterson e t al. (137K) described a dual-flame photometric detector for specific detection of phosphorus and sulfur compounds in gas chromatographic effluents; the first hydrogen-rich flame decomposes the samples, and a second flame produces light emission from the sulfur and phosphorus molecules. In a companion article Patterson (136K) compared the quenchin effects in single- and dual-flame photometric detectors a n f found that the quenching effects of the hydrocarbon background, which are severe in the single flame, are minimized in the dual-flame operation. Moeckel (117K) determined the flame ionization detector response factors for 25 aliphatic sulfur compounds in the 10- to 20-pg range; the molar responses of the sulfides and disulfides are similar and are proportional to the carbon number. Hoshika et al. (72K) used a digital integrator with a flame photometric detector during the gas chromatographic determination of trace amounts of low-boiling sulfur compounds and found that the precision of the technique is comparable to that obtained by the peak height method. The determination of sulfur compounds in gases was of special concern to several investigators. Austin and Robison (5K) discussed the determination of hydrogen sulfide and total sulfur by titration methods. The sensitivity of Pd-gate metal-oxide semiconductor field-effect transistors as a device for the determination of hydrogen sulfide in air was studied a t different temperatures by Shivaraman (158K). Austin (6K) described a coulometric bromine-sensing electrode system with an electrolytic titrator for continuous sulfur monitoring. A sensor for hydrogen sulfide developed by Kiba and Furusawa (89K) depends upon exuding an iodine azide solution from a sintered glass ball which is in the path of the sample flowing in a carrier gas; the sample catalyzes the iodine azide reaction, and the hydrogen sulfide is determined from differences in potential monitored by platinum electrodes, one inside and the other outside the ball. Beskova et al. (12K)determined hydrogen sulfide and methanethiol in natural gas by chromatography on columns containing P,P-oxydipropionitrile, and cumulative sorption of these fractions on a column filled with silica gel which was desorbed for final fractionation on columns of silicone on Chromosorb W and Polysorb. Schiller and Bronsky (153K) reported a gas chromatographic analysis for hydrogen sulfide, organic sulfides, thiols, and carbon dioxide in natural gas and light condensates which uses an electrolytic conductivity detector. Turgel et al. (166K) determined the total sulfur content in an inert as by absorbing the sulfur compounds in three successive atsorbers containing ethanol and analyzing the resultant solutions; organosulfur compounds and hydrogen sulfide are analyzed according to GOST 13380-67; sulfur dioxide is determined turbimetrically after reduction with Raney nickel. Gases containing sulfur in combination with oxygen and/or carbon were analyzed by several workers. Pearson and Hines (138K) determined hydrogen sulfide, carbonyl sulfide, and sulfur dioxide in gases and hydrocarbon streams by gas chromatography with flame photometric detection; three types of columns are needed to achieve separation of the sulfur compounds from each other and from interferences, depending on the matrix. Hoshika and Iida (71K) identified carbonyl sulfide, hydrogen sulfide, carbon disulfide, thiophene, and thiacyclopentane as the major contaminants in town gas by using gas chromatography with a flame photometric detector. The molar correction coefficients for use in chromatographic analysis determined by Torokin et al. (165K) include coefficients for carbonyl sulfide, hydrogen sulfide, carbon disulfide, and sulfur dioxide. Pekhota et al. (139K) determined carbonyl sulfide and carbon disulfide in natural gas by polarography of the products of their reaction with diethyl amine. An improved total conversion type color-producing tube developed by Inui et al. (78K) allows the precise determination of small amounts (1 to 3000 ppm) of sulfur dioxide; the colorproducing reagent, rosaniline hydrochloride, reacts sensitively with sulfur dioxide to become colorless, and the length of the
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decolored layer is proportional to the amount of sulfur dioxide supplied. A device for the detection of sulfur dioxide in a continuously flowing gas suggested by Cheney et al. (23K) uses a piezo-electric quartz crystal coated with ethylenedinitrilotetraethanol which has better stability and gives better detector response than the triethanolamine previously used. The determination of thiol content was the subject of several papers. Kanesaki et al. (86K) found that sodium bicarbonate could be used in place of the usual cadmium sulfate for the removal of hydrogen sulfide prior to the thiol analysis. For the argentiopotentiometric determination of thiols and hydrogen sulfide, Klopov and Makarova (91K) suggested using an antimony rather than a silver sulfide electrode. Hue et al. (74K) determined thiols and primary or secondary amines by adding methyl vinyl ketone and back-titrating the excess ketone with sodium sulfite. Phase-selective cathodic stripping voltammetry was used by Moore and Gaylor (119K) for the determination of watersoluble thiols; the method is capable of determining 1 ppb thiol, and the removal of oxygen from the electrolyte prior to analysis is not necessary. Hille et al. (68K) described a method for determining thiols in aqueous refinery effluents which involves potentiometric titration with silver nitrate solution using a silver-silver sulfide-tungsten electrode; two steps in the titration curve make it possible to determine sulfide and thiol in the presence of each other. Thiolcontaining samples dissolved in water or methanol etc., were analyzed by Bose et al. (14K) by treating the sample with excess copper sulfate and back-titrating with mercaptoacetic acid. Individual thiols were determined by gas chromatography and by mass spectrometry. Cuevas-P and Tellez-G (30K) determined C2 to C4 thiols in gaseous hydrocarbon samples by vapor-phase chromatography on a temperature-programmed Poropak Q column. The gas chromatographic determination of thiols in gaseous petroleum fractions reported by Zygmunt and Staszewski (176K) depends on the concentration of the thiols in sodium o-hydroxymercuribenzoate and sodium p-chloromercuribenzoate solutions. Golovnya et al. (55K) reported the retention indexes of 22 thiols and 7 dithiols on columns of Apiezon M, Silicone OV-17, Triton X-305, and PEG-1000 a t 130 "C. Individual thiols at concentrations of more than 10 ppm were determined by Knof et al. (93K) by negative-ion mass spectrometry using a modified conventional ion source with a hot cathode and a sample pressure of about torr. The same authors (92K) reported the quantitative determination of thiols in hydrocarbons using electron attachment mass spectrometry which determines concentrations of individual thiols with a limit of 10 ppm. Techniques specific for organic sulfides as a type or as individuals was the subject of four papers. Haeusler et al. (65K) determined alkyl or aryl sulfides by iodometric titration with potassium iodate; the end point was detected potentiometrically with a platinum electrode. The retention indexes of 38 normal alkyl sulfides on columns packed with Apiezon M, methylphenylsiloxane OV- 17, Triton X-305, or polyethyleneglycol-1000 on Chromsorb W were reported by Golovnya et al. (56K). The identification of organic sulfides in a naphtha-kerosine fraction, reported by Gusinskaya and Beiko ( 6 3 K ) , involves extraction with sulfuric acid, liquid adsorption chromatography on alumina, and rectification into narrow fractions followed by gas-liquid chromatography on a dual column packed with 10% polymethylsiloxane VKZh and polyethyleneglycol adipinate on Celite-545; comparison of the retention volumes with standards showed that all the sulfides are monocyclic. The same authors (64K) studied narrow-boiling fractions of a sulfide extract by gas chromatography combined with microdesulfurization and identified 40 individual monocyclic sulfides including the cis and trans forms. The possibility of identifying thiophene derivatives in complex organic mixtures using quasilinear luminescence spectra was discussed by Akhobadze et al. ( 2 K ) ; benzothiophenes which do not contain anthracene molecules are detected by strong phosphorescence a t about 850 and 1600 cm-' and fluorescence at about 1300 cm-'; anthrabenzo[b ] thiophenes were detected by fluorescence and absence of phosphorescence. Rafikov et al. (148K) patented a method to detect benzothiophene by adding N-chlorosuccinimide and
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acetone and heating the solution to form a colored compound. McLafferty and Bockhoff (108K) discussed a separation/ identification system for complex mixtures that uses mass separation and mass spectral characterization and, as an example of the specific detection capabilities, reported that less than 25 ppm of thiophene can be detected in gasoline. H u n t e t al. ( i 5 K ) describe pulsed positive-negative ion chemical-ionization mass spectrometry in which the sample is mixed with the reagent gas and introduced into the ion source of a quadrupole mass spectrometer; the polarity of the source potential and of the focusing lens potential is pulsed t o yield separate spectra of the positive and negative ions; determination of aromatic sulfur compounds in the presence of hydrocarbons is facilitated. T h e separation and determination of organosulfur compounds according to type was t.he subject of several investigations. A patent by Kaimai et al. (84K) claims the separation of organic sulfur compounds from hydrocarbons by liquid or thin-layer chromatography on silica gel or acidtreated alumina impregnated with mercuric acetate or silver nitrate. Kaimai and Matsunaga (85K)determined sulfur compounds in high-boiling petroleum distillates by ligandexchange thin-layer chromatography on a mercuric acetate-loaded silica gel plate. Cox and Przyjazny (29K) developed a method for the separation of sulfur compounds by high pressure liquid chromatography and compared it with gas chromatographic separation; the latter is superior for analysis of alkyl and cycloalkyl sulfur compounds (thiols, sulfides, and disulfides) of molecular weight less than 200; whereas the former is more suitable for the analysis of aromatic thiols, sulfides, and disulfides. Moeckel and Zolg (118K) reported the retention indexes of several normal aliphatic thiols, dithiols, sulfides, and disulfides on gas chromatographic columns packed with Carbowax 20M on Chromosorb W AW-DMCS or with SE 30 on Veraport 30; for analytical purposes, the polar Carbowax column is superior. The desulfurization of sulfur compounds on a chromatographic column packed with Raney nickel was studied by Pop1 et al. ( 2 4 6 K ) t o evaluate the possibility of identifying sulfur compounds from the composition of the hydrocarbons in the desulfurization product. Fujii ( 5 1 K ) separated the thiols, mono-, and disulfides by a selective extraction scheme (not detailed in abstract) and chromatographed the resulting fractions on 1,2,3-tris(cyanoethoxy)propaneon Chromosorb W AW; the chromatograph was equipped with a flame photometric detector and was connected to a quadrupole mass spectrometer. Numanov et al. (125K) studied the sulfur compounds in a sulfuric acid extract of fractions boiling 150 to 350 "C; the sulfides were separated by complexing with aqueous silver nitrate and centrifuging; the complexes were decomposed with ammonium hydroxide and identified by mass spectrometry; the remaining sulfur compounds were separated and identified by chromatography on silica gel. A review of the geochemical origin of sulfur compounds in petroleum and kerogen by Orr (131K) includes a discussion of the types of sulfur compounds present. Several groups of Soviet investigators studied the sulfur compounds in the gasoline and diesel fractions of various crude oils. Sulfide and thiophene concentrates isolated by extraction and absorption chromatography from a gasoline and a diesel fuel fraction of Orenburg crude oil were studied by Mel'nikova et al. (112K);mass spectrometry was used to identify thiamonocyclanes and thiaalkanes as the main sulfide components in t h e gasoline fraction and thiamono- and bicyclanes, thiaalkanes, and thiaindanes in the diesel fuels sulfides; the thiophenes in both fractions were mainly alkylbenzo- and dibenzothiophenes. Bol'shakov (13K) studied two jet fuels by infrared and mass spectrometry combined with potentiometry and chromatography; one fuel contained mainly aromatic sulfides and thiophenes; sulfur compounds in the other fuel were principally of the aliphatic type. Infrared spectroscopy was used by Chertkov et al. (25K) for a study of sulfur compounds separated from two straight-run diesel fuels after 10 years storage; the sulfur compounds from one fule contained 93.5% thiophenes arid 6.5% oxidized sulfur compounds, while the second fuel contained 5'2% sulfides, 36% thiophenes, and 1 2 % oxidized sulfur compounds. Zherdeva et al. (174K) separated the 387 to 455 "C distillate of a Kuwait petroleum on silica gel into concentrates of aromatic hydrocarbons and sulfur compounds and studied the
sulfur compounds by infrared and ultraviolet spectrophotometry; sulfoxides with short paraffinic chains, sulfones containing one to three aromatic rings, thiols, thiophenes, and benzothiophenes were determined. Parfenova et al., (133K) studied the sulfides and thiophenes in the diesel fraction of a West Surgut crude by infrared, ultraviolet, and mass spectrometry of concentrates from a separation that involved sulfuric acid extraction t o produce a sulfide-rich concentrate from which the sulfides were further separated by complexation with silver nitrate; the raffinate from the sulfuric acid extraction was subjected to dual chromatography on alumina and silica gel to produce a thiophene/aromatic concentrate from which the sulfides were separated by oxidation to sulfoxides; spectra of the fractions showed that the sulfur compounds were 27 % benzothiophenes, 25% thiamonocyclanes, 8% thiabicyclanes, 7 % thiatricyclanes, 6% naphthenobenzothiophenes, and 5% thiaindanes. Using the separation scheme mentioned above, Parfenova e t al. (134K) compared the sulfur compounds in the 190 to 360 "C distillates of a medium sulfur Samotlor crude with those in the highsulfur Arlan and West Surgut crudes; although the sulfides were qualitatively similar, t h e thiophenes differed substantially-the West Surgut contained considerably more benzothiophenes and less alkyl thiophenes, cyclobenzothiophenes, and dibenzothiophenes. Plyusnin et al. (145K) extracted the organosulfur compounds from the 300 t o 400 "C fraction to Tyumen petroleum by complexing with titanium tetrachloride and studied the extract by ultraviolet, infrared, and mass spectrometry and by adsorption chromatography; the compounds identified included thiophenes and mono-, bi-, and tricyclic sulfides. A method for determining alkyl-aromatic sulfonates in crude oils published by Clementz ( 2 i K ) involves formation of a stable, chloroform-soluble complex between sulfonates and iron-59-labeled ferroin. Dubovaya and Zaraiskii (39K) analyzed xylene sulfonic acids in sulfonation mixtures by gas chromatography with 3 7 ~Bentone 34 and 2 % dinonyl phthalate on Chromosorb; the individual isomers and could be determined after conversion to the more volatile xylenesulfonyl fluorides. Quantitative determination of dimethyl sulfoxide in benzene-toluene-xylene mixtures published by Awwad and Sarkissian ( i K ) involves the use of gas-liquid chromatography with 7.5% of SE-30 plus 0 . 5 7 ~of Carbowax 20M on Chromosorb W. Oxygen. The determination of water in hydrocarbon matrices was the subject of numerous studies. An improved gas chromatographic method for determining traces of water in natural gas was devised by Ertl e t al. (43K);the method uses two columns of glycerol-treated Chromosorb W support with unequal amounts of glycerol on each column and a thermal-conductivity detector; the gas chromatograph contains multidirectional valves which provide for continuous switching between calibration, sampling, and measurement. Leszek and Kosicki (104K)used a combination of azeotropic distillation and gas chromatography (GC) to determine water in oils; first an azeotropic distillation is carried out on the oil, then the distillate is analyzed by GC; a comparison of results obtained by azeotropic distillation alone and by the combination method showed that the combination method was faster and more sensitive, selective, and versatile. A novel method for determining water in oil emulsions by Doughty (34M involves the use of a microwave resonance procedure that is based on the large differences in dielectric roperties of water and oil; the method requires only 0.2 cm of sample, takes only 2 to 3 min to run, and can be used to determine the water content of emulsions containing 0 to 100% water. A thermometric titration method for determining small amounts of water in petroleum products was reported by Kuriya et al. (98K);the sample is dissolved in dry xylene, 0.2 g lithium hydride is added, and the temperature rise is measured; the detection limit is about 0.01% water, and the method is especially useful in the 0.1 to 0.5% range. A patent by Dahms (32M describes an apparatus and method for determining water in gases, liquids, and solids in which the sample is injected into a known volume of Karl Fischer reagent and the absorbance of the reagent is measured by using a colorimeter before and after sample addition; the change in the absorbance is transferred by an electrical circuit into a direct readout of water content. A report by the Japan Petroleum Institute ( 8 2 K ) on the cooperative testing of three variations of the Karl Fischer
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method for determining trace amounts of water in liquid petroleum products covers the methods, data analysis, and the effect of solvents on the coulometric titration. A specially designed cell for the coulometric determination of water was devised by Bardin e t al. (IOK);20 to 30 determinations can be performed without changing the working solutions; 1 X lo-" of water can be determined with a standard error of 0.05%. Awwad and Sarkissian (8K) developed an isothermal gas chromatographic procedure for determining water in N methylpyrrolidone that uses a column packed with 0.5%. Carbowax 20M on Porapak Q with nitrogen as the carrier gas; the lower limit of sensitivity is 1%. Gouw (59K) described several methods for removing emulsified or dissolved water from hydrocarbon mixtures; these methods include mild heating, azeotropic distillation, the addition of chemical reagents, and flash vaporization. Total oxygen by pyrolysis-gas chromatography-particularly the pyrolysis t e c h n i q u e w a s the concern of two papers. Pella and Andreoni (240K) used a short column of carbon coated with 40% nickel for the conversion of oxygen to carbon monoxide; coating with nickel eliminated the adsorption sites on the carbon and improved the accuracy of the procedure. In a patent issued to Honma (70K),the walls of a quartz reactor tube are coated with a carbon film; the tube is packed with platinum-carbon or platinum, and the sample is pyrolyzed and reduced a t 1050 "C; this procedure gives good precision and accuracy because of low blanks and reduced poisoning of the platinum-carbon. T h e identification of various types of oxygen functional groups was the subject of five papers. A method by Sidorov e t al. (259K)for the identification of monofunctional organic groups by gas chromatography involves determining Kovats indices on three columns-a nonpolar stationary phase and two polar stationary phases; the difference between the indices as determined on one polar phase and the nonpolar phase is then plotted against the corresponding differences for the second polar phase and the nonpolar phase; alcohols, ketones. ethers, formates, propionates, and acetates were identified. Rezl and Bursa (150K) developed an analytical method for the on-line identification of organic oxygen compounds using an automated gas chromatography-reactor-frontal gas chromatography instrumental system; identification is based on elemental analysis for the determination of the empirical formula. A high-resolution, high-voltage mass spectrometric method for the analysis of nitrogen and oxygen compounds in petroleum and shale oil developed by Peters and Bendoraitis (142K) permits mass and intensity measurements on u p t o 2000 peaks per section and provides intensity percentages for arbitrary nitrogen- and oxygen-compound classes. In a study by Caude and Rosset (19K) the capability of a new high-capacity ion-exchange silica of the Spherosil type to separate oxygen compounds in petroleum fractions by high-performance liquid chromatography is compared with more conventional macroreticular ion-exchange resins; the ion-exchange silicas give more efficient resolution and higher speed of separation than the macroreticular resins give. Chertokov and Kirsanova (24K) reported a method for detecting and separating oxygen compounds in jet and diesel fuels by adsorption on small synthetic aluminosilicate spheres. Methods for separating and/or characterizing petroleum acids concerned several workers. Several adsorbents including types A and Z zeolytes, silica gel, porous glass, and alumina were studied by Narmetova et al. (223K)for their capability to adsorb naphthenic acids and C5 to C9 fatty acids; silica gels are the best adsorbents for naphthenic acids, while alumina is best for the fatty acids. Several anion-exchange resins were studied by Niyazov and Niyazberdyeva (124K) for their ability to remove naphthenic acids from diesel fuel and kerosine fractions; anion-exchange resins AN 39 and EDE l o p h,ve the best capacity. In a method devised by Shcherbachenko et al. (156K),the naphthenic acid content in aviation kerosine is determined graphically by plotting acidity as mg potassium hydroxide per mL vs. the percent naphthenic acid; the graph is plotted with standard solutions prepared from neutral hydrofined kerosine and naphthenic acids. In a method utilizing preparative gas chromatography developed by Narmetova e t al. (222K) for the direct separation of naphthenic acids, fatty acids, and phenols, a known mixture of phenols, cresols, xylenols, and various naphthenic acids was separated on a xylanized column of Chromaton, and retension
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times of each compound were obtained; a narrow boiling fraction of petroleum acids was then separated on the same GC column, and individual components were identified by comparison of their retention times with those of known compounds. Haines (66K) described a chromatographic procedure for the separation and characterization of acids from distillate oils with boiling ranges of 350 t o 700 "C; the acids isolated from the distillate by anion-exchange chromatography are separated by gel-permeation chromatography to give a concentrate of carboxylic acids; the remaining acidic material is separated on basic alumina to provide subfractions of phenols, amides, and carbazoles. The quantitative determination of phenol and nonylphenol in organic mixtures by ultraviolet spectroscopy reported by Flores et al. (46K) is based on the observation that nonylphenol has absorption maxima a t 276.5 and 282 nm, whereas phenol has a maximum only a t 276.5 nm; runs on known synthet,ic mixtures of phenol and nonylphenol resulted in good accord with calculated concentrations, and the method is much faster than other available analytical methods. Rawat e t al. (149K) reported the chromatographic separation and identification of phenols using papers impregnated with stannic molybdate and developed with 1.0 M sodium nitrate a t p H of 6. Studies of the oxygen-compound composition of petroleum and petroleum distillates were described by several researchers. A kerosine fraction was treated with titanium chloride by Goncharov et al. (57K)to prepare a concentrate of nonhydrocarbon compounds; mass spectrometric analysis showed the presence of two series of ketones with molecular formulas of C,H2,0 and C,H2,-20 and one series of phenols of the molecular formula C,H,,~~,O. In a study of oxygen compounds in a concentrate of nitrogen compounds, Tolmacheva et al. (164K) identified ketone, hydroxy, ester, and acetyl groups. Khodair and Abdel U'ahab (88K) identified a homologous series of straight-chain fatty acids in petroleum by the following procedure: extraction with alcoholic POtassium hydroxide, esterification of the acids with diazomethane, urea adduction, decomposition of the adduct, and gas chromatographic separation; pentadecanoic and nonadecanoic acids were isolated and identified for the first time in petroleum acids. Peroxides in hydrocarbon mixtures were determined by Kirsanova et al. (90Mby mixing the sample with acetic acid, chloroform, and 50% potassium iodide solution and, after keeping the solution in the dark for 30 min, measuring t.he ultraviolet absorbance a t 320, 360, and 440 nm. A procedure for determining aldehydes and ketones in hydrocarbons developed by Kuznetsova et al. (99K)involves treating with 2,4-dinitrophenylhydrazinein benzene and 1% phosphoric acid in heptanol, extracting the hydrazine and acid with water, and treating the organic phase with alcoholic potassium hydroxide, diluting with ethanol, and measuring the absorbance of the hydrazone solution with a blue filter. Nitrogen. Methods for determining total nitrogen in organic mixtures were developed by several researchers. A patent was issued to Parks and Marietta (235K) for a chemiluminescence detection apparatus and method for determining nitrogen; the sample is pyrolyzed in a high temperature furnace in an oxygen atmosphere to form nitrogen oxide which, after drying, is mixed with ozone in a reaction chamber to form metastable nitrogen dioxide which instantaneously relaxes to its ground state; the emitted chemiluminescence is detected by a photomultiplier tube the output of which is proportional to the concentration of the nitrogen in the sample. A procedure developed by Drushel (37K)for determining total nitrogen in petroleum fractions involves a chemiluminescence detector to monitor the nitric oxide produced by open-tube combustion of a micro sample; the method is applicable over a wide range of nitrogen concentrations, but the response is nonlinear above 500 ppm nitrogen; results by this method agree with Kjeldahl values to within 5% average deviation. Yamashita dn Kawaguchi (272K) patented a method that involves combustion of the sample in an oxygen atmosphere followed by oxidation with ozone to convert the nitrogen to nitrogen dioxide which is absorbed in water to form nitric acid which is measured. An automatic analyzer for rapid microdetermination of nitrogen in organic samples was described by Fraisse and Schmitt (48K);the technique involves flash combustion of the sample in helium with 3% oxygen, reduction of nitrogen oxides over
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copper to form molecular nitrogen that is detected by thermal conductivity. Larina and Gel'man (102K) used an automatic analyzer to determine nitrogen in difficultly combustible organic materials by the Dumas method; copper, nickel, or lead oxides are used as the oxidants, depending on the character of the materials analyzed. Abramyan e t al. ( 2 K ) simplified the Dumas-Pregl method by using potassium permanganate as the oxidant and source of oxygen. Determination of nitrogen in petroleum products by y-photon and charged-particle activation published by Gosset e t al. (58Kj is described in the sulfur section of this review. Several methods were designed to determine nitrogen and other elements simultaneously. Grob and Rulon (62K) patented a gas chromatographic method and apparatus for the simultaneous determination of several elements including nitrogen in organic compounds; the method involves combusting the sample in an oxygen atmosphere in the presence of a catalyst and separating the combustion products by gas chromatography; for the determination of nitrogen, the effluent from the gas chromatograph is transported through a reduction zone to an absorption zone; the nitrogen is then desorbed and measured by a secondary detector. In a rapid method for determining carbon, hydrogen, and nitrogen, described by Kyazimov and Mishiev (IOOK),the sample is oxidized a t 900 " C on a copper oxide bed in a stainless steel reactor tube; the gases produced are separated in a gas chromatograph that contains two columns-one to separate the nitrogen and carbon dioxide mixture from water and the second to separate the nitrogen from the carbon dioxide. A method for determining nitrogen and sulfur patented by Fraim (47K) is discussed in the sulfur portion of this review. Two articles published by Miyahara and Takaoka (115K, 116K) describe the handling of volatile liquids and solids in a sealed tube for the ultramicrodetermination of nitrogen in organic compounds; the method involves using a weighing tube of thin-walled capillary containing a capillary of sample; before sealing, the air in the tube is replaced with a mixture of carbon dioxide and methane having approximately the density of air, and the weighing tube is broken by tapping prior to combustion and analysis. The precision and accuracy of a microcoulometric method for nitrogen in residual fuel oil was studied by Katsuno and Hara ( 8 7 K ) ;nitrogen was determined with and without a nonionic surface active agent in the toluene used for dilution; differences in the analytical results from the two methods were negligible, and the accuracy and reproducibility are similar to those obtained by the Kjeldahl method. Hattori et al. (67K) announced a digital total nitrogen analyzer that is based on a combination of the H. ter Meulen method and coulometric titration techniques. Several reviews or reports of cooperative testing were published. The Japan Petroleum Institute (81K) evaluated cooperative test results on the determination of nitrogen in heavy fuel oil by macro- and micro-Kjeldahl, Dumas, and microcoulometric titration methods; the macro-Kjeldahl method using a mercury catalyst was determined t o be the most suitable. Merz ( I 13K) discussed automated methods for the rapid determination of carbon, hydrogen, nitrogen, and oxygen in conjunction with modern data processing equipment and described appropriate programming procedures and evaluation of the results. Methods for the detection of nitrogen in organic compounds were reviewed by Muraca (121K); methods described include Kjeldahl, Dumas, pyrolysis, and alkali fusion, gas chromatography, cleavage reactions, and catalytic denitroenation. Selective detectors for gas chromatography were described in several papers. An ionization detector designed by Kolb e t al. (94K) can be changed so that it can be operated as a universal detector with the same properties as a flame ionization detector, as a selective detector for both nitrogen and phosphorus, or as a specific phosphorus detector. A new nitrogen-phosphorus detector described in the Perkin-Elmer Analytical News (141K) is 50 times more sensitive to nitrogen compounds, 500 times more sensitive t o phosphorus compounds, and 100 times less sensitive to hydrocarbons than the flame ionization detector. Grigor'yan et al. (60K) tested the Hewlett-Packard CHN-185B analyzer with standard compounds and substituted a 7123B recorder for the 3371B integrator; the 7123B recorder was satisfactory for hydrogen and nitrogen determinations but limited for carbon determination.
A method for the separation and determination of hydrogen cyanide in the presence of hydrogen sulfide, developed by Chaigneau and Chastagnier (22K),uses solid lead borate which is inert to hydrogen cyanide in the 0.64 to 54 ppm concentration but reacts with and removes hydrogen sulfide; after removing the sulfide, hydrogen cyanide is determined by the Volhard titration or other analytical method. In a method developed by Hue et al. (74K),primary or secondary amines are determined by the addition of the sample to an excess of methyl vinyl ketone and back titration with sodium sulfite and water using either a mixed indicator or potentiometric method to detect the sodium hydroxide formed by the reaction of the excess ketone with sodium sulfite. The determination of pyridine in subsurface water of petroleum and gas deposits was addressed by Zhuravleva et al. (175K);a phosphorescent solution of pyridine is prepared by addition of 25% aluminum chloride solution and hydrochloric acid to the waters of different mineralization and metamorphism and the phosphorescence spectra are measured a t 395 nm. Three papers described chromatographic or spectroscopic methods for identifying nitrogen compounds. A method developed by Rezl and Bursa (150K) identifies organic nitrogn compounds by determining their empirical formula from elemental analysis obtained using an automated elution GC-reactor-frontal gas chromatography system; details are given on the calculation of the composition and the determination of empirical formula without knowing the amount of substance being analyzed. A high-resolution, high-voltage mass spectrographic method for the analysis of nitrogen- and oxygen-containing fractions of petroleum and shale oil developed by Peters and Bendoraitis (142K) permits mass and intensity measurements on up to 2000 peaks per spectrum and provides intensity percentages for numerous nitrogen- and oxygen-compound classes. A fluorescent spectroscopic method for the identification of aromatic nitrogen heterocyclic compounds was devised by Wagner and Lehmann (170K); compounds separated by thin-layer chromatography or paper electrophoresis are detected by their fluorescence or fluorescence thermochromism; to improve detection, the chromatogram are sprayed with saturated copper iodide solution in acetonitrile and post-sprayed with saturated aqueous sodium carbonate. The separation of nitrogen compounds from petroleum was the concern of Caude and Rosset (19Kj, who studied the capability of a new high-capacity ion-exchange silica of the Spherosil type to separate nitrogen compounds by highperformance liquid chromatography and compared the results with those from more conventional macroreticular ion-exchange resins; the ion-exchange silicas separate faster and give greater resolution than do the macroreticular resins. A liquid chromatographic method for the separation of neutral nitrogen compounds from petroleum distillates and coal products was developed by Oelert and Holguin-Utterman (228K, 129K) using a complexing material containing 3% iron in form of FeC1,.6H20 on Attasorb LVM; dilute ammonia is used for decomposing the nitrogen compound-iron complex and 1,2-dichloroethane for eluting the neutral nitrogen compounds. T h e separation and identification of basic nitrogen compounds were described by several authors. Caude et al. (18K) studied the capability of macroporous ion-exchange resins to adsorb basic nitrogen compounds; quantitative adsorption of 3-methylpyridine is obtained on the cation exchange resin Amberlyst 15 in the hydrogen ion form. McKay et al. (107K) developed an analytical method for the characterization of nitrogen bases in petroleum distillates boiling above 370 " C ; bases are removed with a cation-exchange resin and then further separated into six subfractions using acidic and basic alumina; quantitative infrared spectral analyses showed that the basic compound types in the distillate are pyridine benzologues, amides, carbazoles, and diaza compounds. In a second study by McKay and Latham (106K), the basic nitrogen compounds in high-boiling petroleum distillates from eight crude oils were characterized using methods reported in the previous reference; structures of the compound types were examined in detail using fluorescence, mass, and infrared spectrometry. Several articles reported the removal of nitrogen compounds using titanium tetrachloride as a complexing agent. Plyusnin
ANALYTICAL CHEMISTRY, VOL. 51, NO. 5, APRIL 1979
et al. (143K) used titanium tetrachloride to isolate resinous-asphaltene substances and low-molecular-weight basic nitrogen compounds from petroleum; the weight ratio of titanium tetrachloride t o petroleum required to remove a maximum amount of the asphaltenes and resins was determined. In a second study by Plyusnin et al. (144K), the ratios determined in the previous reference were applied to several petroleum distillate fractions t o remove the nitrogen bases and other heteroatomic compounds for study. Titanium tetrachloride was used by Bembel e t al. ( 1 I K )and Turov e t al. (167K) t o remove the basic nitrogen compounds from petroleum distillates; concentrates were characterized by potentiometric titration and infrared, ultraviolet, and mass spectral analyses; thiazolines, aminosulfides, and aniinothiols were detected by the latter authors. Basic nitrogen concentrates frorn petroleum and petroleum distillates were studied by Baikova et al. ( 9 K ) ,Numanov et al. (126K),Golovchin e t al. (53K, 54K),and Escalier et al. ( 4 4 K ) ;composition of the concentrates was determined b> mass, ultraviolet, and/or infrared spectroscopy (9K, 126K, 53K, 54K)or by gas chromatography ( 4 4 K ) T h e nitrogen compounds in an Egyptian petroleum were studied by Osmaii et al. (132K) using nonaqueous potentiometric titration and lithium aluminum hydride reduction techniques t o obtain type-analysis data; results of this study show that 85 t o 90% of the nitrogen compounds are not reducible with lithium aluminum hydride. The distributions of total and basic nitrogen in the asphaltene, resin, and oil fractions from 34 paraffinic crudes were reported by Sevast'yanova e t al. (155K). T h e use of carbon and nitrogen isotopes in hydrocarbon research and exploration was reviewed by Stahl (160K);stable isotope techniques are useful for environmental identification of organic source materials, evaluation of the influence of migration, recognition of bacterial degradation, quantitative determination of the maturity of organic source materials, characterization of and differentiation between various crude oil accumulations, and correlation of crude oils with source rocks. T h e study of nitrogen compounds in oil shale, oil shale kerogen, and shale oil was conducted by several researchers. In a study to establish the origin of nitrogen compounds in shale oil, Jackson and Decora (BOK) pyrolyzed chlorphS llin and compared the types of nitrogen compounds produced with the types in a light shale oil distillate; their similarities indicate that chlorphyllin can serve as a useful model for the kerogen constituents that yield the nitrogen compounds found in shale oil. Nitrogen compound types in Green River oil shale and its degradation products were investigated by Cummins et al. (31K);benzene-soluble extracts (bitumen) were separated into acid, base, neutral nitrogen, saturate, and aromatic fractions and the types of nitrogen compounds in the first three fractions were determined by potentiometric titration. Frost and Poulson (50K)studied the nitrogen compound types in shale oil produced by in-situ retorting of Green River oil shale; amounts and types of nitrogen compounds in the oil and its various distillate fractions were determined by potentiometric titration methods. Morandi and Poulson (120K)studied the nitrogen types in light shale oil distillates from abovegroundand in-situ-produced oils; distillates were separated according to con~poundclass, and fractions were analyzed by potentiometric titration. S u l f u r , Nitrogen, and Oxygen Compounds. A review ot the literature on the Isolation, separation, and characterization of the heteroatomic components of petroleum was published by Gal'pern (52K). Haines (66K) described a scheme for isolating the acid and base fractions from heavy (350 to 700 "(3 distillates by anion and cation chromatography, respectively, the neutral nitrogen compounds are separated by chromatography over ferric chloride; each of these fractions is subdivided chromatographically to give subfractions which are examined by infrared spectrophotometry. Microcoulometric techniques that require only milligram samples for the determination of sulfur and nitrogen in high-boiling material were presented by Drushel (36K);the techniques allows direct analysis of gel permeation chromatographic fractions without solvent removal; a scanning ultraviolet-visible spectrophotometer with a micro flowthrough cell provides immediate spectral data from chromatographic columns using a stop flow technique. Egiazarov
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et al. (40K) studied the group composition of sulfur and nitrogen compounds in gasoline and kerosine fractions of a Belorussian crude; the sulfur was present mainly as sulfide and residual sulfur, and the major portion of the nitrogen was amides. Eigenson and Ivchenko (4210 found that the residues boiling above 450 "C of Tatar petroleums contained 87 to 90% of the total nitrogen and 59 to 66% of the total sulfur in these petroleums; the distribution of these elements in the asphaltenes, resins, and oils was reported. In a study of the nonhydrocarbon compounds of petroleum by Vylegzhanin et al. ( l 6 9 K ) , the oxygen-, sulfur-, and nitrogen-containing compounds obtained by complexing are separated by extraction and absorption chromatography, and the fractions are studied by ultraviolet, infrared, nuclear magnetic resonance, and combined mass spectroscopy/liquid chromatography. Goncharov e t al. (57K)treated a fraction boiling 140 to 240 "C with titanium tetrachloride to separate a concentrate of nonhydrocarbon compounds consisting mainly of sulfur compounds but including nitrogen and oxygen compounds; spectrometric analysis showed that the sulfur compounds were mainly thiamono- and thiabicylanes and thiophenes; the oxygen compounds included two homologous series of ketones and phenols. Halogens, P h o s p h o r u s , Miscellaneous. The determination of halogens, particularly chlorine, received the attention of several workers. Svajgl et al. (161K) determined 2 to 4 pg of chlorine in a 1-mL sample of crude oil by combustion in an oxygen -hydrogen flame and coulometric titration of the product with biamperometric indication. A method for the determination of chlorides and organochlorine compounds in petroleum distillates by Medvedovskaya and Suvorova (111K) involved titration with mercuric nitrate in the presence of a platinum catalyst with the addition of dichloroethane or carbon tetrachloride to maintain catalyst activity. Lobov et al. (105K) suggested a potentiometric method for the determination of small amounts of chloride in acidified, aqueous extract of petroleum by measuring the emf (silver-silver chloride indicating electrode, glass reference). Nuclear magnetic resonance was used by Ono et al. (130K) for the determination of chloromethanes and chloroethanes in processed petroleum products. Grishin et al. (6ZK)prepared a new stationary phase for gas-liquid chromatography of halogenated organic compounds by photochemical polymerization of 3,3,3-trifluoropropene; the phase has a molecular weight of 1000 to 2000 and is stable to about 250 "C. Iodo-, bromo-, and chloroalkanes were among the compounds studied by Sidorov et al. ( l 5 9 K ) in the development of a gas-liquid chromatographic method for the identification of functional groups; the method involves determining Kovats indices on a nonpolar stationary phase and on two polar stationary phases. Schmidt and Gaylor (154K) pointed out that the high chlorine values obtained on a refinery naphtha were an analytical error caused by sulfur interference with the Dohrmann chlorine measurement and that the refinery problems-high corrosion and tube blockage-that were associated with this naphtha were due t o processing highsulfur crude oil. Six methods that are applicable to halogens or to sulfur [Ehrenberger ( 4 1 K ) ,Gossett et al. (5SK),Grob and Rulon (62K), Hlavnicka ( 6 9 K ) , Kolobielski (95K), Krishnan (96K)I are described in the sulfur portion of this review. Phosphorus in petroleum was determined by Kuriya et al. (97K) by heating the sample to an ash in a hydrogen-oxygen flame, absorbing in aqueous sodium hydroxide, and determining the resulting phosphate by molybdenum blue photometry. Driscoll et al. (35K) developed a method for determining phosphorus in gasoline by flameless atomic absorption spectrometry; aqueous lanthanum nitrate is inserted into a graphite furnace prior to direct addition of the gasoline, and the organic matrix is charred prior to atomization of the phosphorus. A flameless atomic absorption method published by Prevot and Gente-Jauniaux (147K) uses an electrodeless discharge lamp and requires a spectrophotometer with good sensitivity in the ultraviolet. An investigation of the determination of phosphorus in organic media by atomic absorption using a heated graphite atomizer published by Vigler e t al. (168K) shows the necessity of converting organic phosphorus to inorganic phosphorus before the measurement; this is accomplished by ashing on magnesium sulfonate or on magnesium oxide for the determination of tricresyl phosphate
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or of alkyl phenyl phosphite, respectively. Methods applicable to phosphorus and nitrogen [Kolb et al. (94K) and PerkinElmer ( I 4 1 K ) l and two methods applicable to phosphorus and sulfur [Patterson (136K) and Patterson and Howe (137K)l are described in the sulfur and nitrogen portions of this review. T h e determination of arsenic in catalytic reformer feedstocks by flameless atomic adsorption published by La Villa and Queraud (103K) involves adding 5 mL of 1% iodine in toluene, extracting twice with 10 mL of 1 7 ~nitric acid, evaporating the extract to dryness, adding 2 mL of 1%nitric acid, running the sample in the spectrometer, and comparing the results with those for a blank and for standard solutions of arsenic and magnesium. Michelot (114K) determined silicon in coking naphthas contaminated with siloxane antifoam agents by using a direct reading emission spectrometer equipped with a graphite rotating-disk electrode; the naphtha is diluted with mineral oil sufficient to reduce the combustion rate but not to affect the sensitivity.
Analytical and Process Instrumentation J. W. Loveland and C. N. White Suntech, I n c , , Newtown Square, Pennsylvania
In this year’s review, we have retained the same section headings as were used in 1977. Because of the frequent reference to familiar techniques and terminology. we are again using abbreviations to aid the reader in his perusal of the text. Abbreviations recommended by Chemical Abstracts will be used and are 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, FPD, flame photometric detector; std. dev., standard deviation; vis., viscosity: psig, pounds per square inch gauge; a d . , id., outer and inner diameter; in., inch; and HC. hydrocarbon(s). In preparing this review, increased activity was noted in several areas. The use of simulated distillation via GC is increasing, and there were numerous references to applications of GC-MS and LC. Increased activity in the computerization-automation of lab equipment and techniques was also noted. In the Process Instrumentation area, there is an increasing attempt to combine two or more techniques or modifying GCs to resolve on-line analysis problems. The increased use of thermography IR to determine hot spots in boilers and reactors has been noted. X-ray analyzers continue to make inroads in the analysis of S, and metals in petroleum products. The following are recommended for a general reading and cover a broad spectrum of techniques and/or applications.
B R O A D REVIEWS Laboratory. Kajikawa (88L) surveyed the system established by the U.S. Bureau of Standards for standard reference materials and test methods and their role in industrial quality control. Also reviewed are types of petroleum-related reference materials available in the U S . , and Japan Petroleum Institute methods for the prepn. and testing of std. reference samples, illustrated with their N-in-oil stds. Fujita (57L) surveyed instrumental analyses for petroleum products. Topics covered chromatographic techniques, illustrated mostly with lube oil additive analyses, and organic analyses of petroleum and petroleum products by IR, NMR, MS, and inorganic analyses by AA, emission, XRF, and XRD of materials such as sludge, scale, and metals in lubes. Amthor ( 7 L ) discussed principles of laboratory automation in oil industry analytical labs. Included are the mechanization of individual tests (bp, mp, viscosity, d, base no.. pour pt., cloud pt., IR, IJV, NMR, GC, titration, photometry, and elemental analyses), on-line data processing, the suitability of the test for automation, problems of standardization, economic justification, factors affecting the decision to automate and the state of automation in several typical labs in the petroleum industry.
Krieger and Worthy (945) discussed the instruments shown a t the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy in 1977. T h e survey covers photoacoustic spectroscopy, GC/MS systems, GC, LC, AA, IR, UV, and visible spectroscopy, emission spectroscopy, XKD, and XRF. Three papers on GC in the oil industry were presented at a Joint Meeting of the Chromatography and Electrophoresis Group, the Scottish Region, and the Chromatography Discussion Group of the Analytical Division of The Chemical Society held a t Grangemouth, Scotland, Nov. 1976 (128L). Topics treated were heat desorption of trapped vapors from personnel air-monitoring tubes, sources of error in GC analysis and applications of GC in petroleum prospecting. Emergy (44L) surveyed automated chromatography equipment in use a t Monsanto Industrial Chemicals Co., including applications in HC anal. Engelhardt (4SL) discussed the capabilities and limits o f LC and its use in petroleum and coal problems. The prepn. and characterization of sepn. columns, and the advantages of polar and nonpolar stationary phases and of partition, ion-exchange, and exclusion chromatography were covered. Gaylor (61L) reviewed gel permeation (steric excluusion) chromatography for the period Dec. 1975-Nov. 1975. Topics treated include reviews, literature services, apparatus, fundamental studies (non-exclusion effects. resolution, bandspreading, calibration), techniques (branching studies, prep. scale) and applications (analysis of oils and pitches). Alter (6L)surveyed XRF spectrometry, covering equipment and measuring principles, efficiency with respect to accuracy and sample size, sample prepn. and matrix effects, types of equipment available and important applications. In the petroleum industry, applications covered were detn. of P b in fuels, Cu in transformer oils, V and Ni in heating oils, S in crude oils and finished products, C in hydrocarbons, and the combination of XRF with sepn. methods such as TLC. Welz ( I 8 4 L )surveyed the application of A.4 in industrial analysis, covering instrumentation (flame and furnace), analysis of engine, hydraulic and transmission oils of trucks for wear metals, detection of trace metals in wastewater. polymer analysis. and control of metals in fuel oils for high-speed gas turbines. Keil et al. (89L) reviewed inelastic electron tunneling spectroscopy (IETS). Application of IETS to anal. chem. and surface interactions is illustrated by reviewing spectra that have been obtained from 1966 to the present. West (285L) edited the Proceedings of the Sixth Conference on Molecular Spectroscopy organized by the Institute of Petroleum, Hydrocarbon Research Group, Durham, England, March-April 1976. Topics covered include NMR (instrumentation; applications for ( I ) nuclei in low natural abundance, (2) petroleum and coal, (3) solids; spin mapping); Fourier-transform NMR (anal. of crude oils and heavy cuts); IR spectroscopy (multiplex vs. single channel, Laser applications); Raman (petroleum applications); electron spectroscopy (chem. anal., recent developments, depth resolution, surface investigations): molecular spectroscopy (forensic); spectroscopy (polymers, isoprenoid HC in coal and petroleum). Process Analyzers. Utterback ( I 74L)provided a succinct discussion of on-line process analyzers including: sampling systems; pH systems; various spectrophotometric analyzers; quadrupole MS; water and analyzers; LC and GC and various detectors; special application analyzers; computer-analyzer systems; maintenance, calibration, and various factors promoting acceptance of on-line process control. Sandford ( 1 4 4 L ) discusses analyzers as being faster and more reliable than previously. Systems covered were: GC to monitor catalytic crackers and ammonia production units; computer-controlled GC such as Honeywell’s hi-speed multistream analyzer and Foxboro’s GC with pneumatic transmitter; nn-line LC, MS, IR, UV, chemiluminescence, colorimetry, electrochemical systems for ions, pH and 02. Application of some of these analyzers to specific problems are given for process and pollution control. Zakaib (190~5)looks at both on-line and off-line analyzers as they apply to studies and control of major processes such as fractionation, reforming, catalytic cracking, alkylation, and sulfur recovery. Various improvements in process control are discussed and 40 references are given. Broussard (2615)discussed proper sampling techniques with particular emphasis on proportional flow sampling of high
