measure tool wear as a function of drill speed. Kirk et al. (55D) studied grinding fluids by a modified pin-on-disk simulated test employing a hemispherical segment of a grinding wheel rubbing against steel. SEM and microprobe results from the simulated test and from actual grinding tests showed similarities in wear morphology. Raje (830)reported on development of methods for evaluating the performance of oils for traction drives and discussed various hypotheses concerning the relationshirJ of chemical comrJosition of fluids to their tractive capaciiy. The volatilitv of lubricating oils was studied bv RumDf (880)who devdoped relationshps between evapor&ion rite and atmospheric pressure, average boiling point and viscosity using the Noack (DIN 51 581) apparatus. Gardos (350)utilized a quartz-spring mass sorption microbalance in combination with an ultra high vacuum pump to measure evaporation rates of low volatility polymeric lubricating oils. Greases. Stanton (960)presented a paper covering research on analysis of greases by infrared spectrometry carried out by ASTM Technical Division G-IV-4. Of the three methods described for taking IR spectra, the slurry technique proved to be the most precise. Differential thermal, thermogravimetric, and IR analyses were used by Novoded and Bogdanov (750)to study the thermal oxidation stability of complex calcium greases. Thermal analysis was also used by Gar et al. (340)to determine the effect of base oil composition on thermal phase changes in lithium greases. In studying flow properties of greases at high temperatures, Komatsuzaki and Ito ( 5 8 0 ) found the apparent viscosity measured with a cylindrical rotational viscometer dropped sharply at a specific temperature for each grease-thickener combination. Dobson ( 2 5 0 )made a correlation stud of grease flow properties using pipe, concentric cylinder, andlcone and plate viscometers. Culp et al. ( 2 2 0 ) reported on a study of grease shear stability using extended shearing up to 96 h in the ASTM Roll Stability Tester and concluded the D 1831 2-h procedure is too short to give meaningful results. Lindeman and Polishuk (66D)reported on an investigation of the effect of internal radial clearances of 0.0003-0.0008 in. (0.008-0.02 mm) on grease life and torque in ball bearings. Equations for approximating the life of almost any long-life grease as a function of bearing temperature, bearing size, speed, load, and lease com osition were presented in a paper by Booser (1107. SchneiAr (890)presented a paper describing new test procedures for measuring water washoff resistance of greases used in extreme marine environments.
WaX D. R. Cushman and J. W. Schick Mobil Research and Development Corporation, Paulsboro, N.J.
T h e r m a l Conductivity. LeRoux, Smith et al. (9E)examined Fischer-Tropsch waxes, covering thermal conductivity at 20-130 "C, specific volume-temperature curves, average molecular masses, and clear points. The waxes were mainly C34-C150 n-paraffins. Chromatography. Four papers dealt with chromatographic analysis. Azizova et al. ( I E ) studied low-melting paraffins by gas-liquid chromatography. The concentration of n-paraffins increased with increasing melting point of the low-melting wax, and complex forming paraffinic-naphthenic fractions showed a high concentration of normal araffins. Zakupra and Kolosova (I3E)also used gas-liquicfchromatography to analyze high-molecular alkanes (to C51), obtaining more pronounced peak areas of individual compounds using calibration coefficients determined by adjusting conditions (time, temperature) and packing material to those used with model mixtures. Postnov et al. (IOE) calculated physicochemical properties of solid alkanes by programmed-temperature gas chromatography, with the aid of literature data on boiling point distribution and experimental retention temperatures. The calculated molecular weights and densities showed good agreement with standard values. Blau (3E)ap240R
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plied gas chromatography to the analysis of common waxes and wax mixtures, including paraffin and microcrystalline waxes. Spectrometry. Zmudzinska-Zurek (15E) used infrared spectroscopy to determine solid petroleum hydrocarbons in a slack wax fraction. Average number of methyl groups was verified, and n-alkane (from urea adduction) and isoparaffin concentrations were determined. Berthold and Staude ( 2 E ) also analyzed saturated hydrocarbon mixtures by infrared spectrometry to determine structural configurations of fractions from refined crude oil products such as n-paraffins, white oils, Vaseline, and microcrystalline wax. Zenker (14E)described an infrared method for control of paraffin wax oxidation in the presence of boric acid as a reaction control in production of alcohols from paraffins. He found a linear relation between absorption intensity of B-0 stretching vibration in the borate ester wax and the hydroxyl value of the hydrolysis product. Krivjansky et al. (BE)studied the purity of solid petroleum paraffin waxes and ceresins used in the food, cosmetic, and pharmaceutical industries, using UV spectrophotometry to determine aromatic and resinous content, and a combination of UV spectrometry and spectrofluorometry for content of aromatics having carcinogenic roperties. Concentrations as low as 1-10 pb were detected. ghiraishi and Takabatake (12E) also s t u i e d carcinogens in petroleum waxes and synthetic waxes by extraction of benzo[a]pyrene with dimethyl sulfoxide, clean-up of extract on a column of alumina, and determination by spectrofluorometry. Miscellaneous. Six papers covered subjects of general interest, or those which combined several analytical techniques. Ivanova et al. (6E)gave a review, with 33 references, on the chemical composition of peat waxes. Sekine (I1E)discussed low-temperature fluidity of waxy crudes and heavy (fuel) oils, covering changes in flow properties due to wax solidification, test methods, and preventive measures such as the use of additives. Zubarev and Nevolin (16E)studied the solubility of paraffin in etroleum. The amounts of paraffin crystallizing out of petroyeum products and crude oil and depositing on pipe walls while cooling and flowing through pipelines were determined from solubilit curves. Hanna and Mahmoudr(5E) reported on the distribution of n-paraffins in Marine Belayim wax distillate, using zeolite adsorption and gas chromatography. Fal'kovich et al. ( 4 E ) determined n- paraffins by contacting with calcium-A zeolite. Results were more accurate, with lower values than by contacting with urea. Zeolite adsorption data covered nine crudes (or mixtures). Data are also given on fractional crystallization with urea, followed by zeolite adsorption, showing the presence of branched chain and cyclic hydrocarbons. Kamita et al. (7E)made a structural analysis of liquid wax oxidates. Paraffin wax was air oxidized with catalyst and separated into liquid and solid oxidates. The liquid oxides were separated by saponification, extraction, and column chromatography. Each fraction was further characterized by gas chromatography and IR and NMR spectroscopy. Viscosity increased with increased ester content. Esters were mainly lactones and compounds with a t least two ester functions.
Asphalt James R. Couper Department of Chemical Engineering, University of Arkansas, Fayetteville, Ark. 7270 1
The majority of the research work performed during the past two years has been related to the composition of asphalt. The subheadings were arbitrarily selected to facilitate the readability and location of the information. Gel Permeation a n d Chromatography. Some type of preliminary separation of asphalt into its components is necessary prior to the use of a chromatographic separation. The initial separation usually involves a solvent separation or precipitation technique. The fractions obtained by the chromatographic methods may be further subjected to in-
frared spectrometry, NMR spectrometry, ultraviolet spectrometry or x-ray diffraction. Some papers have concentrated on certain generic chemical groups, such as asphaltenes, while others have been concerned with a broader analysis. The majority of the research reported in the past two years has been performed by foreign investigators. Gel permeation chromatography was the technique used by Reerink and Lijenga (75F) to prepare calibration curves for asphaltenes and bituminous resins. These curves related elution volume to molecular weights. The molecular weight determinations were obtained using an ultracentrifuge. The British Coke Research Association ( I I F )reported using the gel permeation technique to determine the bitumen content in tar-bitumen blends. Altgelt ( 6 F ) reports the use of successive gel permeation chromatography, n-pentane precipitation, and alumina column chromatography to separate asphaltenes, maltenes, and maltene subfractions. Kasahara et al. (443') compared the differences in the physicochemical properties of Kuwait and California asphalts using gel permeation, IR spectroscopy, surface tension measurements, and torsional braid analysis. In a study of the structures of pitches from coal and petroleum, Itoh et al. (39F) used a variety of techniques including gel permeation chromatography. Greben (30F) reported the use of paper chromatography to separate microamounts (0.001-0.0011 g) of bituminoids using hydrophobic chromotographic paper. He suggested the use of luminescence analysis using glacial acetic acid and chloroform. Gas chromatography followed by UV spectrometry was employed by Greinke and Lewis (31F) to identify nine polynuclear aromatic hydrocarbons, four methyl substituted and five unsubstituted hydrocarbons in an environmental restoring procedure. Kawahara (4727)reported the use of electron-capture-detector gas chromatography to determine minor components in asphalts as evidence of water pollution sources. Felscher (25F) described a gas chromatographic method for determining higher normal paraffins (C15-53) from bitumens of various origins. Gumenetskii et al. (34F)reported a gas-liquid chromatographic procedure for analyzing petroleum asphaltenes by oxidizing with air in an alkaline aqueous benzene medium to obtain steam-distillable acids, water-soluble acids, hi h molecular weight water-insoluble acids, and benzene-solutle acids. The water-soluble acids are separated by means of liquid chromatography. Bitumens from Green River Shale, Athabasca tar sands, and Niagara dolomite were examined using a combination of gas and liquid chromatography as reported by Marschner et al. (59F). There were numerous citations during the past two years which involved the studies of the fractionation and characterization of bitumens. Although liquid chromatography was used as one of the initial separation steps, no similarity in analysis procedures beyond this step were noted. Al-Kashab and Neumann ( 3 F )followed the initial alumina-silica chromatography steps with IR and NMR techniques on an Iranian asphalt. Aksenova et al. ( 2 F ) fractionated petroleum asphaltenes on a silica el column using petroleum ether, CC14, CsH6, and CsHs-EtbH mixtures. Subsequent IR determinations revealed a linear dependence of the absorption intensities on the molecular weights of the fractions. Bunger (14F)characterized the physical and chemical properties of a Utah tar sand bitumen using chromatography in conjunction with ion-exchange coordination complexing, gel permeation chromatography, fluorescence, IR, and mass spectroscopy. Kolbin (51F) dereloped a rapid method for determining the group composition of the maltenes in petroleum bitumen using a silica gel column and washing with a variety of materials such as EtOH-CsHs, 10%HCl, 10%KOH solution, and hot water. The eluate was collected on a moving chain and passed through an evaporator, where, at 725 "C oxidation of the separated substances took place. The gaseous products passed through silica gel to a katharometer detector. Analysis time was reported to be 25 to 30 min. Petrossi (7OF) used a thin-layer chromatographic technique separating the samples into five asphaltic and malthenic fractions. He claimed less overlap of fractions than in previous chromatographic methods. Ali (5F)proposed a chromatographic technique for determining elemental sulfur in bitumen from Athabasca sands. Grudnikov and Bakhtizina (33F)patented a rapid method for determining the content of asphaltenes in bitumens by
dividing the sample into two parts; one is dissolved in isooctane; the other in benzene. A drop of each solution is transferred to chromatography columns and the solvents are removed by evaporation. The same set of solvents is then used to elute corresponding groups of compounds from maltene and bitumen samples. The contents of maltenes and asphaltenes in the bitumens are calculated from peak areas on the chromatograms. The analysis time is about 30 min. The same authors (32F) reported refinement of a method for obtaining asphaltene concentrations using a marble chromatographic sorbent. Asphaltenes were obtained from the difference in peak areas on resulting chromatograms. Zalka (89F)reported an adsorbent activated with picric acid as a final step in the study of the composition of Hungarian and Russian asphalts to separate aromatic hydrocarbons having a different number of rings. Kolbin et al. (51F) also reported a semi-automatic liquid-adsorption analyzer which was used to determine group chemical compounds of maltenes. Analysis time was reported to be 30-40 min. Inverse gas chromatography of petroleum asphalts was reported by Usacheva et al. (83F) but only the title had been translated. Barbour et al. (9F) studied asphalt-aggregate interaction using IGL chromatography. The asphalt fractions served as the stationary phase and interactions were studied by observing the retention characteristics of known volatile test compounds. Asphaltenes showed a reduced interaction probably due to agglomeration. Aggregate surfaces (quartzite) were found to catalyze oxidation of the less polar fractions. Chromatographic separations have been used to study hydrocarbons present in tar seepage in the Gulf of Mexico (52F), and in determining the composition of bituminoids (30F). NMR, IR, AA, and X-ray Methods. Many methods have been mentioned in the previous section which also subsequently use the methods described here. An arbitrary decision had to be made concerning where the emphasis should be placed. If the primary means of separation is NMR, IR, AA, or x-ray methods, references then appear in this section. Kasahara (43F) used the NMR spectra of the aromatics, resin, and asphaltene fractions of a Kuwait asphalt to determine asphalt deterioration during storage. The spectra yielded structural parameters which showed the aromatics and resin fractions contained four and six rings per unit sheet and that they remained during heat treatment. Fujishima et al. (26F) compared the chemical characteristics of natural asphalt, Athabasca tar, sand, and petroleum asphalt using NMR spectral analysis. Smith et al. (81F)performed an analytical study which was designed to establish the reproducibility of a petroleum pitch system as a function of the sampling periods, and to obtain information on the molecular structures and compositions of these materials using NMR techniques. Smith et al. (82F)in another article used the Wilkains NMR method for deriving composition and structure of organic molecular types on pitches. The procedure could be extended to asphalts. Katayama (46F) presented a correlation between the structure of coke and the structural properties of raw aromatic heavy ends using NMR and x-ray techniques. NMR data in conjunction with elemental compositions and molecular weights were used to gain insight into the structures that com osed percursor materials derived from petroleum using N M g d ata reported by Smith (80F). Cetner and Wachal (15F) reported the use of NMR spectroscopy to follow chemical changes during the oxidation of air-blown asphalts. Furuta et al. (27F) used NMR, x-ray diffraction, elemental analysis, and other techniques to follow the chemical structure and graphitizing characteristics of solvent extracts from tar pitches, Cetner and Wachal (16F) reported in a later study the use of NMR spectroscopy to determine the percentage carbon in aromatic and aliphatic structures as well as the degree of aromatic centers substitution with atoms excluding hydrogen. Primak (74F) reported the use of a vanadiumporphyrin complex as a standard for the concentration of paramagnetic centers for the NMR control of the oxidation of bitumens. Significant work has been performed by the Bureau of Mines Laramie Energy Research Center in Wyoming using IR techniques. Dorrence et al. (21F) used the infrared examination of oxidized asphalts before and after sodium borohydride reduction or oxime formation to show that ketones, probably of the alkyaryl type are the oxidation products. No ANALYTICAL CHEMISTRY, VOL. 49, NO. 5, APRIL 1977
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aldehydes were detected. In further work, Petersen et al. (68F) identified dicarboxylic anhydrides as a significant product formed upon the oxidation of asphalts. Petersen (69F)later demonstrated a quantitative method using differential infrared spectrometry to determine the presence of ketones, dicarboxylic anhydrides, carboxylic acids, and 2-quinolone compounds in asphalts. Kawahara et al. (48F) successfully characterized asphalts and heavy residual fuel oils using a combination of IR s ectrophotometry, data treatment of selected peaks, l a t a transformation, and descriminant-function analysis in conjunction with a computer. Moustafa (64F) identified components of asphaltic and coal tar pitches using IR techniques. Mozharowskii et al. (65F) identified the composition of bitumens from kimberlite pipes using IR spectroscopy and x-ray diffraction analysis. An IR study of the chemical structure of bituminoids extracted from clayey rocks with trichloromethane was reported by Shaks and Ageeva (78F). Trace inclusions of solid bitumens using IR spectroscopy were presented by Faizullina et al. (24F) Petrov and Shtof (71F) mentioned that they could determine the structures of stabilizers in emulsions of asphalts by means of infrared spectroscopy. Maragil and Svintitskikh (58F)proposed molecular structures for asphaltenes and their pyrolysis products at 380 "C using both IR and NMR data. X-ray techniques have received considerable attention during the past two years as an analytical tool. All of the reported work has been Russian. Godun et al. (29F)developed a rapid determination of normal paraffin hydrocarbons in bitumens, and presented calibration curves prepared from model mixtures of n-paraffin and relative x-ray scattering intensity. Posadov et al. (72F)discussed an x-ray diffraction study of asphaltenes indicating that the molecular structure of the asphaltenes consists mainly of packets of horizontal layers containing polynuclear aromatic and heterocyclic molecules. Makhonin and Petrov (55F) used an x-ray technique to establish that asphaltenes separated from crude petroleums and from the stabilizers of their emulsions have identical stj-uctures. Bodan et al. (10F)studied the structure of petroleum products usin x rays. Aromaticity, ag lomerate distance, and lattice were letermined as structura parameters. Flameless atomic absorption spectroscopy with neutron activation analysis was used for the determination of the vanadium content of 30 crude oil residues by May and Presley (63F). Pate1 (67F)presented a rapid and convenient method for extraction and subsequent spectrophotometric determination of the bitumen content in bituminous sands. Miscellaneous Composition Studies. The remaining references relate to various papers in which the major part of the discussion is chemical composition. A significant contribution by Rostler et al. (76F) was reported on the fingerprinting of highway asphalts. A data bank was established by the Federal Highway Administration consisting of 400 punched cards containing pertinent information on individual asphalt specimens. Certain composition and behavior parameters were used for identifying asphalt samples. Maragil and Ramazaeva (56F) developed a technique of relating the ratio of the number average molecular weight of asphaltenes to the weight average molecular weight. If the ratio was approximately equal to 3.5, it indicated a very high degree of polydispersion of asphaltenes. Masiarzyk and Radosz (61F)described a stain test which was used to correlate group compositions and physical properties of asphalts. Zhelezko et al. (92F) defined a dispersion coefficient as the ratio of the sum of the resins and aromatics to the sum of asphaltenes and alkane-naphthene hydrocarbons by weight. They studied the effect of asphalt composition on aging of asphalt concrete by noting the increase in compressive strength with the increase in dispersion coefficient. Budnik and Gun (13F)reported on the distribution of heteroelements in highly oxidized bitumens. They noted that the bitumens and asphaltenes had increasing C to H ratio with increasing degree of oxidation and that the sulfur content decreased and nitrogen content remained essentially constant. Clugston et al. (19F) isolated sulfur compounds from bitumens derived from the Athabasca tar sands. These sulfur compounds were predominantly alkyl-substituted benzo- and dibenzothiophenes.
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Buczko et al. (12F) used a neutron reflection method for determing bitumen content in asphalt concrete. May and Presley (62F)determined trace elements in both asphalts by a neutron activation analysis. Several articles were concerned with the study or isolation of asphaltene content of asphalts using extraction or precipitation techniques. Antipenko and Titov ( 8 F ) reported a separation technique to obtain two different asphaltene fractions based on extraction of petroleum by polar solvents followed by separate deasphalting of the extract and residue. Zenke (90F) developed a new series precipitation technique to better characterize the asphaltene composition of bitumen using eight precipitating agents. He reported on 69 primary, blown, weathered, and heat treated bitumens of different origins. Zenke (91F),in a later article, by simple precipitation methods, noted that asphaltenes may be grouped into hard, medium, and soft fractions using hydrocarbon solvents or solvent pairs of different strengths. Wilkens (85F) presented a method for determining the presence of asphaltene and petroleum resins by precipitating in warm ethyl acetate, filtering, and then extracting the resin from the residue with n-pentane. This step was followed by a benzene extraction of asphaltenes. Yen (878') presented a review of 80 references concerned with the complex structure of petroleum asphaltenes. Gurarii (353')studied the effect of dispersions of asphaltenes in various tar-hydrocarbon systems. The results showed that with increases in asphaltene content, molecular weight, cohesive strength, softenin and brittle points increased. Glozman et al. (28F) oxidizefa Siberian asphalt to obtain brittle and highly plastic high-melting bitumens which were subsequently separated into maltenes and asphaltenes. Asphaltenes were 1.8 times more soluble in maltene oils from the brittle bitumen than in those from plastic bitumen. Asphaltenes from the plastic bitumen had higher polarity than those from the brittle bitumen. Katayama et al. (45F)presented a new compositional analysis method for pitches and compared the results with those obtained by the van Krevelen and Brown-Ludner methods. Kang and Chu (42F)and Woo et al. (86F)reported on the determination of acid numbers of asphalts. Constantinides et al. (20F) performed a study to verify whether the electron microscope could detect -structural changes in asphalt after treating the sample with cold or hot n-heptane and whether the results could be used to predict the service behavior of asphalts. Felscher (25F)presented the final report on API Research Project 62 involving the thermodynamics of hydrocarbons from petroleum. Asphalts were also included in this study. Air Blown Asphalts. During the past two years there has been limited research reported concerning air-blown asphalts. Kinnaird (49F)reported on the basic molecular structures in chromatographic fractions of air blown asphalts. Haley (36F) found that air blowing a Kuwait asphalt at 200 "C rather than 245 "C increased the degree of polymerization and reduced internal cross-linking, dehydrogeneration, and decarboxylation. A variety of analytical and physical techniques were employed in the study, including gel permeation chromatography, NMR, IR, and vapor pressure osmometry. Pyrolysis of Asphalts. A number of studies have been reported concerning the degradation of asphalts by pyrolysis. Maragil and Ovintitskikh (57F) studied the decomposition of asphaltenes, into light hydrocarbons, CI-C~,and heavier hydrocarbons with molecular weights of about 350. In the gaseous products, methane predominated followed by ethane and propane in that order. The heavier hydrocarbons consisted of naphthenic-paraffinic compounds. Chernova et al. ( I 7 F ) pyrolyzed asphaltenes from petroleum lake muds and from peat bituminoids in the range of 200-900 "C. The asphaltenes,from the petroleum sources were more aromatized and condensed than from the other sources. Martynov et al. (60F)used a pyrolytic gas chromatographic technique to study the bituminous-asphalt components of petroleum. Posadov et al. (73F) reported a DTA, thermogravimetric, and gasvolumetric study of the pyrolysis of asphaltenes and presented observations on the structure and nature of thermal transformations. Wieckowska (84F) used a slow programmed heating process up to a 873 K to determine the composition of asphalts and heavy petroleum-coking residues. A patent by Krc (53F), assigned to Shell Oil Company, described a total-recovery thermal-analysis method for determining yields
in relation to boiling points (up to 1600 O F ) of microsamples of carbonaceous materials containing both volatile and nonvolatile components. The method was demonstrated on asphalt, pitch, and straight-run residues. Asphalt Rheology. Heukelom (37F) suggested a method of characterizing asphalts using their mechanical properties. A Bitumen Test Data Chart was developed relating penetration to viscosity as functions of temperature. Ermolaeva et al. (238') measured the kinematic viscosities of petroleum bottoms and seven road asphalts a t 90 to 200 "C. For asphalts originating from the same feedstock, the kinematic viscosity was found to be a linear function of the softening point. Altgelt and Hade (7F) performed tests on fractionated and unfractionated asphaltenes precipitated from asphaltic, naphthenic, and paraffinic residua. The results showed that asphaltenes aggregated in solution to varying degrees, and this aggregation affects the viscosity of the solutions. They also found that aggregation affects the susceptibilities of various asphalts to oxidation and to blending. The aggregation also contributes strongly to irregularities in the viscosities of asphalt mixtures. Kandahl and Wenger (4IF) measured asphalt viscosity a t 77 O F with a vacuum capillary viscometer. The results obtained on an experimental Asphalt Institute vacuum capillary viscometer were compared with those on a sliding-plate viscometer. At the 95% probability level, no significant differences were observed between data obtained with the two viscometers using AC-20 asphalt cements with penetration values of 40-112. Nakajima (66F) reported that linear relationships between viscosities at the inflection points of the fluidity curve and the viscosity parameter predicted by Wright's method were in good agreement with experimental results on Venezuelan blown and synthetic asphalts. These relationships permitted the prediction of asphalt flow properties from a small number of viscosity and composition data. Asphalt Paving. Hills et al. (38F)reported a good correlation between rutting and creep tests on asphalt mixes. The results indicated that internal deformation mechanisms in the mixes were the same for both rutting and creep, and that creep behavior could be used to estimate rut depth a t any stage during laboratory tests. It was proposed that this prediction technique could be extended to rutting of road and airstrip pavements, as shown by a qualitative correlation between creep behavior and road behavior of a heavily traveled road. Lee (5427) extended previous studies on the use of pollution abatement-derived sulfur to modify asphalt and asphaltpaving mixtures. The addition of the sulfur to the asphaltconcrete mixtures significantly increased the stability, resistance to water action, and tensile strength of the compacted mixtures. Zakar (88F) presented a brief survey which covers the difficulties in matching the properties of road bitumens from different crudes with user requirements and previously developed standards. Miscellaneous Technology. The production of asphalt was discussed in three papers. Ryabova et al. (77F) presented the effect of deasphalting temperature on the composition and properties of solid hydrocarbons in deasphalted oil. The yields of solid hydrocarbons in the oil, the viscosities, the melting points, etc. were reduced as were the asphalt yields, softening points, coking capacities, and asphaltene contents. Akhmetova and Glozman ( I F ) described a method of selecting feed composition for asphalt production. The proportions of asphalts from as many as four different processes were blended in a mixture to meet asphalt standard requirements. The method involves the use of a ternary graph of hydrocarbon, asphaltene, and resin contents. Aleksandrov et al. (4F) described the expansion of a plant for producing paving asphalts in vertical-column reactors. The reactors were unique in that the lower part was an oxidizing section and the upper part was a condensing section, fitted with cascade trays to prevent the escape of asphalt. Ciesielski (18F)investigated the sulfur contents in asphalts and asphaltenes using nuclear activation analysis on domestic, Middle East, and Venezuelan asphalts. The results showed that the Venezuelan asphalt had a significantly higher sulfur content than the other two, and that the sulfur was concentrated in the asphaltenes. The Venezuelan asphalt also had a high asphaltene content, whereas the other asphalts did not differ significantly in their sulfur or asphaltene contents. Ensley (22F)used a differential microcalorimetry technique
to study the kinetics of association in a gilsonite, roofing asphalt, a B-3076 Federal Road Asphalt, and an Idaho Road Asphalt. Paving asphalts were found to associate reversibly. Low activation energies and heats of reaction indicate that association proceeds by physical dipole interactions, and not by a polymerization mechanism.
Catalysts J. Free1 Gulf Research and Development Co.,Pittsburgh, Pa.
Elemental Analysis. A microdetermination of sulfur in aluminosilicates and molybdenum-alumina catalysts was described by Sagdullaeva and Shamsiev (67G). Catalyst samples were treated in hydrogen at high temperature, the product hydrogen sulfide absorbed in an alkalilacetone solution, and sulfide ion titrated against mercuric acetate. Wilson and Marczewski (94G) determined fluorine in petroleum processing catalysts with a 2-ppm limit of detection. Samples were fused with a mixture of sodium borate and sodium and potassium carbonates, and the melt was dissolved in water. Fluoride ion was determined with a fluorine selective electrode, after buffering to pH 6. Roschi and Matschiner (66G) used an inverse voltametric procefure to determine traces of lead in reforming catalysts. The catalyst was dissolved in either sulfuric acid or a potassium pyrosulfate flux, the solution neutralized with ammonia and extracted successively with dithizone and aqueous hydrochloric acid. Naono et al. (58G) compared the successive-ignition-loss method and reaction with methylma nesium iodide for determining surface water in porous oxifes. Results were nearly identical, but reaction time for the latter method depended on pore size and took up to 17 h in small pored materials. The determination of sodium in zeolites was discussed by Grba (36G), who described simple dissolution procedures for A- and X-type zeolites. Sodium was determined flame photometrically in the resulting solutions. Results were reproducible with a relative error of f2%. Analysis time was 20-30 min. Manoliu et al. (52G) also used a flame photometric method for determining sodium, silicon, and aluminum in molecular sieve zeolites. Dissolution was achieved by alkali fusion. An unusual method for determining the zeolite content of zeolitic catalysts was devised by Benesi (9G).Liquid benzene was added and its subsequent vaporization rates were correlated with pore diameter and used to determine the amounts of various zeolites incorporated in amorphous oxides. Zakharov and Aitkhozheva (98G) employed an amperometric titration to determine palladium in catalysts using a platinum indicator electrode. Successive dissolution in nitric and sulfuric acids was used to dissolve the palladium. Palladium was determined spectrophotometrically as a divalent complex by Mas'ko et al. (54G) Of several complexing agents studied, furylpentadienal thiosemicarbazone proved the most suitable for extracting palladium from catalysts. Manoliu (51G) discussed the spectrophotometric determination of palladium as the 2-nitroso-1-naphthol complex and compared the method with an atomic absorption technique. The complexation procedure gave errors as high as 16%with catalysts containing 0.1-1% palladium, whereas the atomic absorption method was accurate to f3%. Potter (63G) used atomic absorption spectrometry to determine palladium and platinum in automotive exhaust catalysts and reported a standard deviation of l%and an accuracy of f2%. The spectrophotometric determination of platinum as a tetravalent chloro complex was examined by Vorlicek and Dolezal(89G), who applied the method to reforming catalysts. Hulanicki and Jedral(41G) determined platinum in reformin catalysts, using biamperometric titration of the dissolve8 platinum. An EDTA complexometric method for determining nickel and calcium in hydrogenation and gas reforming catalysts was reported by Dutta et al. (25G),while Fernandez et al. (30G) used an EDTA complexing technique for determining nickel ANALYTICAL CHEMISTRY, VOL. 49, NO. 5, APRIL 1977
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