are covered. Lumpkin (87H) has combined high resolution mass spectrometry and low voltage techniques to quantitatively analyze the trinuclear aromatic fraction of a high sulfiir- and nitrogencontaining rrude. Idmtifications were made by precise mass measurement of the molecule ion and then of the fragment ions as a test of the assumed structure. Tunnicliff and Wadsworth (14611) have described a stepwise regression program for the quantitative interpretation of mass spectra that does not require prior knowledge of sample composition. The program mathen~atically chooses, from a library of spectrit, a suitable small group that, when multiplied by proper concentration factors and summed, gives the best least sduares fit to the sample spectrum. The library may contain up to 150 reference spectra with data for 110 masses on each. The program has been used iuccessfully for a h o - y e a r period on a wide variety of samples. References to chemical or electrochemical methods for hydrocarbons are largely confined to the analysis of olefins or certain aromatic s2ecies. A colorimetric method for the determination of small amounts of acetylene using Ilosvay reagent has been desc eibed by Xmamehyan and Moroz (,$€I). Siggia and Stahl (127“) have proposed a method for the detection of acetylenic compounds that involves formation of the mercuric acetate complex and measurement of the ultraviolet absorption of the addition product a t 260 mp. It wa5 applicable to all compounds having terminal acetylenic goups that the authors tested. However, it failed in some cases nhen internal acetylenic linkages 15 ere involved. A polarographic method for thta determination of napthalenes in petrolcam products has been described by Lezhneva and Kruglov (8411). The total naphthalene content of gas oils can be determined with an accuracy approching 5%. Benzothiophene interferes with the analysis if it is present in conctntrations greater than about 570.
Nonmetal Elements and Compoimds 1. C. Morris, D. R. lafharn,
and W. E. Haines, Bureau o f Mines, U. S. Deportment o f the Interior, l(mxnie, Wyo. SULFUil
A
of the chemical and physical methods for ioncentrating and identifying sulfur compounds in petroleum was prepared by Thompson and coworkers ( I E S J ) . A ialytical methods for determining sulfm compounds in petroleum gases mere reviewed by Donchenko ( 3 7 4 . Techniques for total sulfur by x-ray absorption, with REVIEW
a discussion of their application and accuracy, were surveyed by Servasier (1S6J). Total sulfur in gases was determined by mass spectroscopy in a method described by Khvostenko and Sultanov (73J). Total sulfur in casing-head gases was determined by Radulescu (728J) using activated carbon absorption. Microamounts of organic sulfur were determined by several new techniques. A combustion technique with a colorimetric measurement of sulfur dioxide formed was reported by Dokladalova (QbJ),and by Chen, Tan, and Chou (26J). Durbetaki and Alvarez (39J) reported a novel method for the determination of 0.2-500 ppm total reducible sulfur based on desulfurization via activated Raney nickel in a specially designed apparatus; the nickel sulfide formed reacts with mineral acids to generate hydrogen sulfide which is absorbed in an alkaline potassium iodate solution; iodine is liberated by acidification, extracted with toluene, and measured spectrophotonietrically a t 307 mp. Traces of sulfur in organic and inorganic substances were determined by Takeuchi and Tanaka (151J), using catalytic hydrogenation followed by measurement of hydrogen sulfide by the methylene blue method. llicrogram quantities of sulfur in low-boiling petroleum distiliates were measured by Pitt and Rupprecht (123J) in a colorimetric method based on reduction of sulfur by Raney nickel in an oxygen-free atmosphere. Krafft and Wagner (79J) discussed the application and accuracy of a method for determination of small quantities of sulfur using Raney nickel reduction and titration of the hydrogen sulfide with mercuric acetate. Traces of sulfur and halogens were determined in a new combustion apparatus described by Pichl (1815), with B photometric measurement for halogens and a gravimetric finish for sulfur. Combustion of the sample folloived by reduction of the resulting sulfur oxides mas recommended in a procedure developed by Takeuchi, Fujishima, and Wakayama (160.1) for the determination of microamounts of sulfur in organic compounds. Dokladalova, Korbel, and Vecera (36.J) calcined samples in an open quartz tube a t 750’ C in a current of air to determine small amounts of sulfur in organic subslances. I n determining macroamounts of sulfur in petroleum and its products, hlalissa. llachherndl, and Pel1 ( 9 5 4 found combustion rates t o be an important parameter and discussed the relation of sulfur percentage and sample size to combustion rates. To determine sulfur in volatile organic substances, Stoerzbach ( 1 4 7 4 used a calorimetric bomb with complexometric back-titration of excess barium added to the
ignition products. A rapid method for determination of sulfur, adaptable for the measurement of halogens and metals, which was developed by Barat uses a special stainless and Laine steel injection burner, and titration of the sulfuric acid with barium chlorate. The Schoniger method was modified by Farley and Winkler ( 4 6 4 to provide a flow of oxygen to the combustion bottle, the products from which were passed into a Wickbold absorber for analysis. The Soci6tB Kationale des Petroles d’Aquitaine (I@J) published a method for the continuous determination of sulfur in gas streams; the method employs catalytic oxidation followed bf conductometric determination of the sulfur dioxide formed. 1n’kova, Jiakarov, and Klement’eva (6SJ) propose a rapid method for sulfate determination which uses barium chloride and potassium chromate. Total sulfur determination by reduction to hydrogen sulfide was proposed by Krumbholz and Jaeckel ( 8 1 4 who reduced the sulfur catalytically; small amounts of hydrogen sulfide were determined by the methylene blue method, and larger amounts measured by iodometric titration. Methods employing x-ray and gammaradiation absorption were discussed by Gorski and Grabczak ( 5 2 4 who compared several techniques for determination of total sulfur in organic products. Servasier (136J), who used iron-55, tritiated zirconium, or tritiated titanium as radiation sources, measured sulfur in petroleum gases. The sulfur impurities in naphthalene were measured by lIaklakov and coworkers (9u) using iron-55 as the radiation source; Matsushima (101J) used a similar method to determine sulfur in benzene and heavy oil. Pyrah ( 1 2 7 4 recommended x-ray absorption using a titanium target and a Geiger tube for quick determination of sulfur in heavy distillates and residual fuels. Improved accuracy was obtained in sulfur analyses by Lyast and Vshivtsev (92J) when two radiation sources mere used, one being maintained as a reference A scheme of analybis for determining types of sulfur compounds in petroleum products was the subject of several papers. Koch and Paul (78J) presented a scheme for the analysis of sulfur compounds in petroleum gases. X method for the group analysis of sulfur compounds in low-boiling petroleum distillates was developed by Maskova and Loipersbergerova (1005). The characterization of the sulfidic structures in petroleum products was described by Prinzler (126J). The sulfur compounds in transformer oils were characterized in a procedure reported by Krol, Rozhdestvenskaya, and Kucheryavaya (804. -4 discussion of methods for the group analysis of sulfur compounds VOL. 39, NO. 5, APRIL 1967
171 R
in petroleum was presented by Luk'yanitsa (9OJ). A colorimetric method for determination of disulfides, developed by Cuzzoni and Lissi (33.4 distinguished between aliphatic, heterocyclic, and aromatic disulfides. Free sulfur, hydrogen sulfide, thiols, sulfides, and disulfides were determined qualitatively and quantitatively in a method recommended by Rubinshtein and Krivova ( I S H ) . Microwave spectra were used by Pozdeev and coworkers ( 1 2 5 4 for qualitative analysis of complex mixtures of organosulfur compounds. Corrosive sulfur was determined by oscillographic polarography in a method described by Kiselev (74J). Total and corrosive sulfur in insulating oils were determined by Rey and Sutter (1SOJ) using a combination of metallic mercury treatment and combustion. Hydrogen sulfide was determined by Baranenko and Krivosheeva (7J) using cadmium acetate absorber solution and back-titration of excess cadmium, thus avoiding interference from olefins. Hydrogen sulfide in gases was measured by Shul'gina, Arutyunova, and Blyumshtein (1S8J) using cadmium acetate absorption and iodometric titration. Low concentrations of hydrogen sulfide were determined by Malkova and Radovskaya (96J) by colorimetric measurement of the blue complex formed with ammonium molybdate. LeRosen ( 8 6 4 determined hydrogen sulfide and thiols in alkaline solution by gas chromatography using acid-coated Chromosorb ahead of the analytical column. A mixture of gases containing hydrogen sulfide was analyzed by Staszewski, Pompowski, and JanAk (145J) using gas chromatography; results from the use of several stationary phases were reported. Hodges and Matson ( 5 9 4 reported the results of using combinations of two supports and four stationary phases in the gas chromatographic analysis of a mixture containing carbon dioxide, carbon oxysulfide, hydrogen sulfide, carbon disulfide, and sulfur dioxide. A qualitative potentiometric determination of hydrogen sulfide in jet fuels, reported by Englin and coworkers (42J), established detection limits as low as 10 ppb. Jacobs, Braverman, and Hochheiser (66J) determined hydrogen sulfide in the air in the parts-per-billion range using an alkaline cadmium hydroxide absorber. Huygen (62J) collected samples of hydrogen sulfide from the air using filter paper impregnated with potassium zincate; efficiencies a t various temperatures and humidities were reported. hfeasurement of the fluorescence of a fluorescin dye before and after its reaction with hydrogen sulfide in air samples was used by Andrew and Nichols (SJ) to determine concentrations as low as 0.5 ppb. 172 R
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ANALYTICAL CHEMISTRY
Microamounts of hydrogen sulfide in petroleum waters were determined by Nedorost and Paralova (109J) by photometric measurement after reaction with p-aminodimethylaniline. A patent was issued to the Union Carbide Corp. (156J) for equipment designed for continuous polarographic determination of low concentrations of hydrogen sulfide in nitrogen streams. Thiols in gasoline were determined by Bloembergen and Vermaak (16J) using alkaline extraction and gas chromatography. Brand and Keyworth (225) identified and estimated amounts of thiols in gasoline by precipitation with silver nitrate followed by regeneration with hydrogen sulfide and resolution by gas chromatography. A procedure for amperometric titration of thiol groups with the rotating platinum electrode was described by Nedi6 and Berkei (108J), and by Romovacek and Holub ( 1 S I J ) . A potentiometric alkali-acidimetric determination of thiols was developed by Singh and Varma (139J); the hydrogen ion was liberated by iodoacetate solution and reacted with excess sodium hydroxide, which was back-titrated with hydrochloric acid. Suchomelova and Zjrka ( 1 4 8 4 used lead tetra-acetate in glacial acetic acid for potentiometric titration of thiols. Thiols in gasoline were determined by Oelsner and Heubner (114J) using plumbite extraction followed by complexing with Komplexon(II1) and back-titration of the excess Komplexon with a zinc salt. Ellman ( 4 1 4 found that when a thiol was treated with a reagent with a bis (substituted-4-nitrophenyl) disulfide structure a brilliant yellow color developed which was proportional to the concentration of the thiol. Seventeen aliphatic and aromatic sulfides, plus other sulfur compounds, were studied by Ratovskaya and Gavrilova (I29J) using anodic derivative polarography. Thompson and coworkers ( 1 5 2 4 evolved a systematic procedure of concentration and identification of sulfur compounds in petroleum fractions, and identified a group of chain sulfides in the distillate boiling from 1 1 1 O to 150' C. Disulfides were determined polarographically by Obolentsev, Gavrilova, and Bulatova ( 1 1 2 4 , and studies of the interference caused by the presence of elemental sulfur and thiols were reported. The ultraviolet absorption spectra of 10 sulfides, 2 disulfides, and 3 thiophenes were reported and discussed by Obolentsev and Lyubopytova ( 1 1 S J ) . A novel qualitative test for organic compounds containing bivalent sulfur, based on the color development with bromine vapor in the presence of aniline, was described by Bayfield, Clarke, and Cole (9J).
Organic sulfur compounds were sep-
arated chromatographically, converted to sulfur dioxide in a flame ionization detector and determined conductimetrically by Coaper ( S I J ) . A sulfurspecific microcoulometric cell was described by Adams and Jensen ( 1 J ) for measurement of sulfur compounds from gas chromatographic separations. The sulfur compounds in petroleum samples were determined by hIartin and Grant (98J) using gas chromatography with microcoulometric sulfur detection. Thiophene was determined polarographically by Jaworski and Bogaczek (67J) in a procedure designed to minimize interferences. hlartin and Grant (99J) developed a method for thiophene determination based on the decomposition of nonthiophenic sulfur over alumina a t 500' C, followed by gas chromatography with microcoulometric detection of sulfur. The mass spectra of 23 alkylthiophenes were obtained by Foster and coworkers (47J), who discussed the correlations of the spectra with compound structure. Carbon disulfide in benzene was determined by Grant and Vaughn (6SJ) using a gas chromatograph with a n electron capture detection system. Low concentrations of carbon disulfide in benzene were measured by White (161J) and by Maklakov and Gorelov (9SJ), using ultraviolet spectrophotometry. The measurement of the amounts of sulfur oxides in the atmosphere received increasing attention. Stephens and Lindstrom ( 1 4 6 4 proposed a spectrophotometric determination based on the reaction of the sulfur dioxide with ferric iron and 1,lO-phenanthroline. Sulfur dioxide and sulfur trioxide were determined by Bond, Mullin, and Pinchin ( 1 8 J ) ; the gas sample was passed over crystalline oxalic acid where sulfur trioxide reacted to form carbon dioxide and carbon monoxide which were reA solved gas chromatographically. tracer technique was used by Crone, Evans, and Noyes (15?J) to evaluate colorimetric and conductometric methods for sulfur dioxide analysis. Lisle and Sensenbaugh (89J) proposed modifications in the method for determination of sulfur trioxide and acid dew points in flue gases. Studies of color enhancement and stability in the spectrophotometric determination of sulfur dioxide in air were carried out by Scaringelli, Saltzman, and Nieman ( I S S J ) , and by Huitt and Lodge ( 6 I J ) . Omichi (116J) improved the procedure for the colorimetric determination of atmospheric sulfur oxides by lead dioxide cylinder method. Sulfur dioxide in air was measured by the change in the impedance of the sample when the sulfur dioxide was absorbed in aqueous acidified hydrogen peroxide solution, as reported by Leong, Dowd, and LIacFarland (85J). Strips of
filter paper impregnated with potassium carbonate were used by Fukui ( 4 9 4 to collect samples of sulfur dioxide, nitrogen dioxide, and chloride ion from the atmosphere; conventional methods of analysis were then employed. Ammonia interference in the acidimetric determination of sulfu? dioxide in the atmosphere was studied by Paccagnella (118 J ) ; the interferences caused by the presence of nitrogen dioxide were investigated by West and Ordoveza (16OJ), and by Pate and coworkers (12OJ). Hesse (57J) developed a special packing for a sulfur dioxide detection tube. NITROGEN
A method for classifying nitrogen compounds in petroleum into five different types-strongly basic nitrogen, three types of weak11 basic nitrogen, and nontitratable nitrogen-was developed by Okuno, Latham, and Haines (115J). The method involves titration of the crude oil with perchloric acid in acetic anhydride solution before and after reduction with lithium aluminum hydride. Prior separation or concentration of the nitrogen compounds is not required. Bender, Sawicki, arid Wilson (11J) developed a method fcr the fluorescent spot test detection and spectrophotometric determination clf carbazoles and polynuclear carbazoles Tetraethylammonium hydroxide gave a more stable fluorescent color and fluorescence spectra than reagents pre.riously used. A method was developed by Snyder and Buell ( 1 4 1 4 t o characterize and routinely determine certain types of nonbasic nitrogen compnnds in highboiling petroleum disfillates. Ion exchange, linear elution adsorption chromatography, and ult *aviolet spectrophotometry were used for determining indoles, carbazoles, anc benzocarbazoles in straight run, heavy gas-oil distillates. The composition of the neutral nitrogen compounds in Russian crude oils was investigated by Bezinger, Gal'pern and Abdurakhmanov ( 1 5 4 . Using potentiometric titration and infrared spectral analysis, the authors found that 85-100~, of these neutral nitrogen compounds mere disubstituted aromatic amides. Coy elin (29J) identified 2-quinolones in t i e heavy gas-oil fraction of a Califcrnia crude oil. These compounds comprise 0.4 weight % of the gas-oil and 0.05 weight yo of the crude oil. Latham, Okuno, and Haines ( 8 4 4 reviewed the literature on the nonbasic nitiogen compounds in petroleum; pyrroles, indoles, carbazoles, benzocarbazoles, phenazines, benzonitriles, and amides have been identified in petroleum stocks. Several investigato~s modified the Dumas method for d(:termining nitro-
gen. Farley, Guffy, and Winkler (45J) used a Coleman analyzer for the automatic analyses of lubricating oils and additives a t the 20-ppm level; the nitrogen compounds were adsorbed on alumina, which was then analyzed. Mitsui ( I O U ) developed an improved nitrometer that is operated without a leveling bulb and has a large capacity for potassium hydroxide solution. .4 simplified apparatus which permits rapid and accurate nitrogen analysis by the Dumas method was described by Tuchscheerer (1554 ; the advantages of the method are that the potassium hydroxide solution cannot be drawn back into the combustion section, the liquid surface has constant absorption characteristics, and the time required for analysis is reduced without loss of accuracy. Pippel and Romer (122J) described a modified Dumas micromethod for determining nitrogen in compounds that normally do not react readily with carbon dioxide during combustion; alkali-free nickel oxide was used as the catalyst. Otea ( 1 1 7 4 used sodium hydrogen carbonate as the source of carbon dioxide in the method. Inoue, Sayama, and Takata ( 6 5 J ) , in determining high percentages of nitrogen, used 60- to 100-mesh copper oxide and maintained the stationary furnace a t 900' to 975' C. Weitkamp and Korte (159J) developed a fully automatic apparatus for the combustion analysis of carbon, hydrogen, and nitrogen in 0.1- to 0.9-milligram samples. X method to determine carbon, hydrogen, and nitrogen in samples in the 0.01- to 1.0-milligram range was developed by Koch and Jones ( 7 7 4 . The applicability of the Kjeldahl procedure for estimation of nitrogen in heterocyclic ring compounds was studied by Mookherjea (106J) who found that the digestion period could be reduced two to four hours by using a combination of vanadium pentoxide catalysts with selenium. Kuehnert and Bauer (8dJ) discussed the advantages of using boric acid as the absorbing solution during the distillation step of the Kjeldahl procedure. Lunt (91J) used an alkaline stannite to reduce nitro groups and make the nitrogen available for Kjeldahl determination. Chumachenko and Mukhamedshina ( 2 7 4 determined nitrogen by heating the organic materials with metallic potassium in a steel bomb a t 1000°, then extracting with ethanol. Xitrogen in the extract was converted to tetracyanonickel anion with nickel sulfate, and excess nickel was titrated complexometrically with a nickel-complexing reagent. A microcombustion technique developed by Norris and Flynn (111J) to determine nitrogen in petroleum down to the 1-ppm level involves burning
the sample in an oxygen atmosphere over platinized asbestos; the nitric oxide formed is treated with sulfanilic acid and 1-naphthylamine to produce a red dye, whose absorbance a t 535 mp is compared to a calibration standard. Trutnovsky ( 1 5 4 4 automated a previously described microcombustion method for determining nitrogen in organic compounds. Klemm and Airee ( 7 5 4 investigated the geometry of adsorption of heterocyclic nitrogen compounds by gas-solid adsorption chromatography. Columns of alumina and quinolidine-treated alumina were used to obtain retention times and heats of adsorption for a number of nitrogen compounds. Baker, Lachman, and Corwin ( 5 J ) separated a number of porphyiin compounds by column-partition chromatography. A column consisting of dimethylsulfoxide on a silica support with cyclohexane as the mobile phase was used to make the separation. OXYGEN
The Unterzaucher procedure for the determination of total oxygen was the subject of several studies. Schoeniger ( 1 3 5 4 summarized 10 years' experience with the titrimetric microdetermination by the Unterzaucher method. Mandrykina ( 9 7 4 suggested removal of sulfur from the pyrolysis products before conversion to carbon monoxide; sulfur is removed by passage over silver a t 700-720" C. AIietasch and Horacek (103.J) preferred hydrogen to nitrogen as carried gas, particularly when sulfur was present, because of ease of removal of hydrogen sulfide. Campiglio ( 2 4 4 suggested several improvements in the Unterzaucher procedure. Kuznetsova, Stolyarova, and Dobychin ( 8 3 4 pyrolyzed the sample at 900' C in an atmosphere of helium in the presence of nickel-containing carbon black and determined carbon monoxide by gas chromatography. Boys and Dworak (19J) pyrolyzed in the presence of carbon, eluted the pyrolysis products through a molecular sieve column with helium for separation of the carbon monoxide, which was measured by a katharometer. Goetz (51J) decomposed a 2- to 30-mg sample in a quartz vessel a t 1120' C and, using hydrogen as a carrier gas, swept the products over carbon to a chromatographic column for measurement of carbon monoxide. After examination of several modifications of the Scheutze-Unterzaucher method, Belcher, Davies, and West (1OJ) suggested pyrolysis over platinized carbon a t 900' C, use of copper and soda asbestos to remove interfering gases, and gravimetric determinations after conversion of carbon monoxide to carbon dioxide with Scheutze reagent a t room temperature. VOL. 39, NO. 5 , APRIL 1967
173 R
An automated instrument for compounds dissociable below 900" C was reported by Ebeling and ,Marcinkus ( 4 0 4 ; the sample was pyrolyzed at 900" C in a n alumina reaction tube in the presence of platinized carbon; after removal of the halogens and the sulfur, the carbon monoxide was oxidized to carbon dioxide and determined gravimetrically. The oxidation of carbon monoxide and other pyrolysis products by iodine pentoxide and anhydroiodic acid was studied by Kainz and Scheidl (70J, 7 1 4 . Other approaches to the determination of total oxygen included a method by Frazer ( 4 8 4 which involved mixing the sample with an organic reducing agent such as phenyl thiourea and reacting in a bomb a t 1050' C ; the volumes of hydrogen and carbon monoxide are then measured. Berezkin, Mysak, and Polak (1SJ) suggested converting the oxygen to carbon monoxide b y reaction with carbon black, hydrogenating the carbon monoxide on nickel to methane for detection, using a gas chromatograph with a flame ionization detector. Yoshida and Goshi (162J) studied the sources of error in the activation analysis by fast neutrons; nitrogen-16 produced by exposing oxygen to 14-Mev neutrons mas measured. Mott and Orange (1074 suggested reducing the beam and target effects on the precision of activation analyses with fast-neutron generators by using a defocused D beam with beam aperture and by rotating the sample and comparator around an axis parallel to the beam axis. Oxygen dissolved in liquids or mixed in gases continued to receive attention. Dowson and Buckland (S8J) described a process in which the oxygen concentration is continuously determined in a flowing fluid medium; the apparatus consists of a measuring sensor responding to oxygen, an oxygen-absorbing galvanic cell with a silver wire cathode and an anode consisting of finely divided cadmium, which is arranged in a tube filled with an inert carrier gas. A patent by Courtaulds Ltd. ( 3 0 4 described a method for continuous detection of high oxygen concentration in combustible gases; the mixture is brought in contact with a high temperature element, thus inducing a reaction between oxygen and the combustible gases in the mixture; the ternperature of the gases is taken after their contact with the element. Hersch ( 5 6 4 patented a trace analyzer which consists of two conductive electrodes contacting a nonconducting porous diaphragm between them; the cell is filled with an electrolyte such as 5N potassium hydroxide; a n external electric current, sufficient to cathodically reduce the oxygen, but insufficient to decompose the water is 174 R
ANALYTICAL CHEMISTRY
applied during use and the current is measured for the determination. A device for continuous measurement of dissolved oxygen in organic liquids and in water was developed by Capuano ( 2 5 4 ; it involves a thallium and calomel electrode pair; the oxygen, in the presence of water, reacts to form thallium ions which are reduced at the thallium electrode. Collins and Hoenig (28J) reported an oxygen detector, which is sensitive to oxygen at lo-" torr, that depends upon the increase in work function of a tungsten filament when chemisorption of oxygen occurs. Paris, Gorsuch, and Hercules (119J) developed a procedure for the titration of uncombined oxygen and antioxidants which involves potentiometric or photometric titration with 2,4,6-tri-tert-butylphenoxy free radicals. Several workers determined water in hydrocarbons by its reaction to produce hydrogen. Starshov and Galeeva (l/tSJ) passed light hydrocarbon vapors through a tube of calcium hydride; the hydrogen produced was separated from the light hydrocarbons using molecular sieves and the hydrogen volume measured. An automatic microanalyzer described by Liebetrau, Daehne, and Xohnke (87J) is based on the reaction of water with calcium hydride; the resulting hydrogen reacts with palladium dichloride to give hydrogen chloride, which is absorbed in water and determined by measuring the electrical conductivity, the pH, or by titration. Berezkin and coworkers (12J) determined tiaccs of water in olefins by the quantitative chromatographic determination of hydrogen evolved in the reaction of the water with a solution of sodium aluminum hydride in diethylene glycol dimethyl ether. Starshov and Voevodkin (1-444 determined traces of water in gases and liquids, passing the sample through a column filled with sodium and determining the resulting hydrogen by gas chromatography. Modifications of the Karl Fischer technique for the determination of water continued to appear. Archer and Jeater (4J) suggested using ,V-ethylpiperidine as the catalyst, detecting the end points with a polarized electrode system applied to a p H meter, and making 5-minute drift measurements after completion of a titration. Schober and Strittmatter (1344 found direct Fischer titration by the deadstop method unsuitable for insulating oils with less than 20 ppm water and suggested an indirect nitrogen-purge Fischer method. Gruess ( 5 4 4 described an automatic micropipet for the simple and exact determination of the standard strength of Karl Fischer reagent solutions. Small amounts of water were determined by Polyakov ( l 2 4 J ) using the reaction with ethyllithium to form lith-
ium hydroxide and ethane followed by either fixing the excess ethyllithium with vanadium pentoxide and determining the reacted ethyllithium, or by measuring the amount of liberated alkali after taking up the excess ethyllithium in a benzyl chloride-tetrahydrofuran mixture. Huebl, Schatzberg, and Glassman (60J) determined small amounts of suspended water by mixing water-soluble bicarbonates and organic acids with the vvater-insoluble organic liquid in a gas-tight bomb and measuring the pressure increase due to release carbon dioxide. Pallah (4SJ) described a manometric method for determining water and dissolved gases in mineral oil in which water is condensed a t -78' C and the amount (down to 0.5 ppm) is determined by vapor pressure; noncondensible gases are measured (down to 0.25 ml/liter) volumetrically; oxygen is then eliminated with white phosphorus; and the oxygen content calculated from the pressure difference. Medveczky and Sebestyen (102.l) prepared an indicator reagent capable of detecting about 0.002% water by adsorbing bromochlorophenol blue on barium sulfate and adding sodium diethylbarbiturate. Voelker and White (15885) developed equipment to monitor the moisture content of refinery streams continuously by detecting changes in the electrical capacitance of a remote cylindIica1 condenser immersed in the stream; the condenser is packed with a granular desiccant, which permits measurement of less than 1 ppm of dissolved moisture. Szalay, Varallyai, and Porzsolt ( 1 4 9 4 suggested the Szabo-Kagy apparatus for the determination of the water content in mineral oils by the measurement of the dielectric constant. Iilugrnan (76J) studied the accuracy of electronic apparatus for moisture determination and suggested several improvements. In connection with a study of the bubble column slurry reactor, Farkas (/tdJ) developed a new method for determination of hydrocarbon-in-water solubilities which requires commonly available equipment. Carbon monoxide may be determined in gas mixtures by means of its color reaction with his-(1,lO-phenanthro1ine)palladium chloride and subsequent measurement of the extinction of 550 mp, accoiding to a paper by Burianec and Burianova ( 2 3 4 . Nirzayanov and Berezkin (IO4J) determined traces of oxygen and carbon monoxide in propylene chromatographically on a molecular sieves column. Jobahazi (69J) compared absorbents used for carbon monoxide in the Orsat apparatus and suggested a 2-pipet system, consiqting of a sulfuric acid-cuprous oxide suspension and ammoniacal copper solution. Doering and Mueller ( S L J ) determined carbon oxysulfide in synthesis gas by the
iodine-azide reaction after removal of carbon dioxide and hydrogen sulfide. Mixtures of monohydric phenols (C6C,) were analyzed by Adlard and Roberts (M)by silylation of the phenols before gas-liquid chromatography in a capillary column. Lindeman and Nicksic (88'5) suggested the characterization of individual alkylphenols by proton magnetic resonance after acetylation. C'rump (325) resolved mixtures of siinple alkylphenols from kerosine; the phenols, coupled as p-nitrophenylazo dyes, were separated by two-dinien iional chromatography on silica gel impregnated with sodium hydroxide. 3krynnikova and Matveeva (14 0 4 sepirated phenols by steam distillation and bromination; the end of bromination was determined amperometrically. Zubkova and eoworkers ( 1 6 3 4 used thin layer chromatography on alumina for the separation and identification of alkylphenols and aminophenols in mineral or synthetic oils. The determination of the phenols used as additives or solvents was the subject of several papers. Berthold and Drescher (14J) determined 2,6-ditert-butyl-p-cresol in turbine oils by infrared spectioscopy, measuring the intensity of the 1168 cm-' band of the hydroxyl group on the tertiary carbon atom. The same additive was determineti by Braithwaite and Penketh (SOJ) using a pr0ced.u-e involving preliminary separation by distillation with methand followed hy analysis based on colorimetry, infrared spectroscopy, or gas-liquid chromatography. Braithwaite, I'enketh, and Underwood ( d f J ) separated 2-methyl-6-tert-butyl-p-creso1 from gasoline by column chromatography, oxidized witl- potassium ferricyanide, coupled with diazotized p-nitroaniline, and determi led spectrophotometrically. In'kova and Piyunkina (6;J) described a method for the determination of phenol and alkylphenols in additiveir. Norikov and Vetchinkina (11OJ) separated various lerf-butylphenol additives gas chromatographically using; Apiezon N as the stationary liquid phase. Geller, Shevrhenko, and Rastorguev ( 5 0 4 suggested two methods for the determination of phenol and cresol used in solvent extractions; one method is based on removing the solvents from the oil with aqueous sodium carbonate and the other removes them with steam distillation; in both methods phenol and cresol concentration is determined colorimetrically. 3lixtures of petrcleum acids were separated by Bock and Behrends (17 4 by esterifying and t k en separating the methyl esters by dir,tillation and gas chromatography with polyethylene glycol and 2-ethylhexyl sebacate as the stationary phase. Jenkins (685) desrribed the determinrition of carboxylic
acids and esters in petroleum distillates and residues by infrared spectroscopy; this paper includes a survey of recent reports in which infrared spectroscopy was applied to petroleum. Hill and Hill (68J) separated mixtures of free aromatic acids by gas chromatography with hexameth y l d i s i l a z a n e - t r e a t e d Chromosorb W coated with 15y0 Carbowax 20M. Harlow and Morman (555) described automatic ion exclusion-partition chromatography for acids involving separation on a column of sulfonic acid exchange resin and continuous automatic titration to pH 8.5. The oxygen-containing compounds resulting from the pyrolysis of light oil weIe isolated and characterized by Shor, Chertkov, and Gol'din (1375) using chromatography on KSM silica gel. Keil and Rentrop ( 7 2 4 found that the chief products of mineral oil aging (acids, esters, lactones, and alcohols) could be determined by infrared spectroscopy; the undiluted oils, after removal of sludge, were examined in the regions 1700 to 1800 and 3100 to 3600 cm-l. Banerjee and Budke (65) extended a spectrophotometric method for the determination of peroxide for use with unsaturated compounds.
Metals in Oil H. A. Braier, Gulf Research & Development Co., Pittsburgh, Pa.
A
methods which recently have evolved, activation analysis and atomic absorption spectrometry are gaining popularity among analysts for the determination of a variety of chemical elements in petroleum and related materials. I n the 3.25-year period covered by the last two reviews, only two papers in each one of the above-mentioned techniques were abstracted, while in the 2-year period covered by the present review, six papers dealing with atomic absorption and eight involving activation analysis were published. The following papers are arranged by analytical methods. Activation Analysis. Fast neutron activation associated with y-ray spectrometry and computer programming has been applied by Hull ( W K ) to the determination of nitrogen, phosphorus, chlorine, zinc, and barium in lubricating oils. The use of computer data reduction in neutron activation analysis has been described by Steele (44K). Oxygen in hydrocarbons and barium in lubricating oils were determined by Gibbons (13K) as examples of the application of 14-m.e.v. neutron generators inactivation analysis. Additives in lubricating oils have been indirectly measured by determining barium, phosphorus, iron, sulfur, and chlorine by fast MONG THE INSTRUMENTAL
neutron activation ( I d K ) . Phosphorus, sulfur, and zinc were also determined in motor oil additives by radioactivation analysis by Nagy and Saokolyi (36K). Nuclear reactor irradiation followed by chemical separation and y-ray spectrometry has been used by Malvano (SWK) to analyze crude oils, crude asphalts, and polyphenyls for traces of nickel and cobalt. A similar approach was successfully applied by Colombo et al. ( 7 K ) to the systematic analysis of 11 metals in petroleum products. Ten elements in the parts-permillion and parts-per-billion range were identified and measured in some Italian oils and asphalts by Ciuffolotti et al. ( 6 K ) using an elaborated reactor irradiation technique. Atomic Absorption Spectrometry. This analytical technique has been used to rapidly determine traces of iron, copper, and nickel in gas oil feedstocks ( 1 K ) ; and nickel, down to 0.05 parts per million in catalytic cracking feedstocks by Trent and Slavin (46K). Several problems affecting the evaluation of lead in gasolines, especially the chemical natuie of the lead standard, have been studied by Dragnall and West ( Q K ) . A procedure for atomic absorption determination of lead in gasoline has been described by which lead can be evaluated with an accuracy of about 1% of the amount present (47K). Atomic absorption spectrometiy was applied to the determination of wear metals in lubricating oils: copper, chromium, iron, lead, and silver in concentrations ranging from 0-100 ppm have been determined by Burrows et al. ( 5 K ) in used lubricating oils with good reproducibility and without interference problems, The rapid determination of iron, copper, silver, magnesium, chromium, tin, lead, and nickel in lubricating oils has been reported by Means and Ratcliff ( S S K ) . Finally a procedure has been described by Sprague and Slavin (43K) for the rapid analysis of used aircraft lubricab ing oils for nickel, chromium, lead, copper, silver, and magnesium, a t the rate of 14 seconds per sample per element, with a precision of about 5%. Emission Spectrometry. A technique was described by Kahonitz ( 2 6 K ) for emission spectrographic determination of a variety of metals in liquid mineral oil products, uring a rotating electrode. An indirect determination of vanadium and nirkel has been reported by Petho ( S 6 K ) in which a pair of graphite electrodes are immersed in the oil, and heated to 1000" C before being excited by a high tension spark. Nine elements, including nickel and vanadium] have been estimated in petroleum and bitumens by Berman ( s K )first combusting the sample with a buffer mix and then exciting the ashes in a .F-ampere d.c. arc. Determination of trace elements in crude oils has been achieved by VOL. 39, NO. 5, APRIL 1967
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