(25N) Sebrell, W. H., Jr., Ed., "The Vitamins; Chemistry, Physiology, Pathology, Methods", Second ed., Volume V. New York Academic Press, 1972. (26N) Seifert, R. M., Miller, C. F., J. Assoc. Offic. Anal. Chem., 56, 1273 11973). (27N) Sheppard, A. J., Prosser, P.. R.. Hubbard, W. D., J. Am. OilChem. SOC., 49, 619 (1972). (28N) Sklan, D., Budowski, P., Anal. Chem., 45, 200 (1973). (29N) Uebersax, P., Mitt. Befiete Lebensm. Hyg., 43, 469 (1972); Anal. Abstr., 25, 1231 (1973). (30N) Uebersax. P.. Hueni. K.. ibid., p 478: Anal. Abstr., 25, 1247 (1973). (31N) Van de Weerdhof, T., Wiersum, M. L., Reissenweber, H., J. Chromatogr., 83, 455 (1973). (32N) Van Gend. H. W., Z. Lebensm.-Unters.Forsch.. 153, 73 (1973); Chem. Abstr., 79, 144940k (1973). (33N) Wagner, B., Wandinger, H.. Mschr. Brau., 25,
157 (1972); Anal. Abstr., 24, 459 (1973). (34N) Williams, R. C.. Baker, D. R., Schmidt, J. A,. J. Chromatogr. Sci.. 11, 618 (1973). (35N) Winkler, V. W., J Assoc. Offic. Anal. Chem., 56, 1277 (1973). (36N) Winkler, V. W , Yoder, J. M., J. Assoc. Offic. Anal. Chem., 55, 1210 (1972). Miscellaneous (1P) Gemert. J. T. van, Talanta. 20, 1045 (1973) (2P) Henningson, R. W., J. Assoc. Offlc. Anal. Chem., 55, 504 (1972). (3P) Hibbert, H. R., British Food Manufacturing Research Association, No. 53 (1968). (4P) Institute of Brewing Analysis Committee, J. lnst. Brewina. 78. 187 (19721. (5P) Kramer, A.,"Quality Controi'For The Food industry", Vol. 2, Avi Publishing Company, Westport, Ct., 1973. (6Pj Macleod. A. J., "instrumental Methods of Food Analysis", Halsted, New York, NY,
1973. (7P) Office International du Cacao et du ChocoiatMethods of Analysis, A. Gordian GmbH 8 Co KG-London: Food Trade Press Ltd. (8P) Pettinati, J. D., Swift, C. E., Cohen, E. H.. J. ASSOC.Offic. Anal. Chem., 56, 544 (1973). (9P) Siebert. K. J.. Tech. Quart. Master Brew. Assoc. Am., 9, 205 (1972); Anal. Abstr., 25, 3417(1973), (1OP) Smith, B. G., J. Chromatogr.. 82, 95 (1973). (11P) Stewart, T. F., British Food Manufacturing Research Association, No. 61 (1969). (12P) Technicon Corporation, "Advances In Automated Analysis. Technicon International Congress, 5th. New York, 1970", Vol. 2, Futura Publ. Company, Mt. Kisco. NY. 1972. (13P) Thompson, M.. Howarth. R. J., Analyst. 98, 153 (1973). (14)) Wilson, J. M., Kramer, A., Ben-Gera. I., J. FoodScl., 38, 14 (1973). (15P) Yeransian. J. A., Sloman, K. G.. Foltz, A. K., Anal. Chem.. 45, 77R (1973).
Solid and Gaseous Fuels Elizabeth A. Hattman, Hyman Schultz, and John F. Smith U.S. Energy Research & Development Administration, Pittsburgh Energy Research Center, Pittsburgh, PA 752 73
This article surveys methods of sampling, analyzing, and testing solid mineral and gaseous hydrocarbon fuels and follows the general format of the previous reports. The period covered extends from October 1972 through September 1974.
SOLID FUELS This section covers publications concerned with methods of sampling and chemical and physical testing of coal, coke, and related materials. Extensive use was made of Chemical Abstracts and Fuel .4bstracts as sources of reference. Some selectivity was necessary so the publications included were those considered most pertinent. SAMPLING AND PROXIMATE ANALYSIS The trend in this area is toward automated and continuous analyses. Nuclear techniques are frequently used. Mohrhauer ( I 4 A ) designed an apparatus for automatically obtaining a coal sample and preparing it for laboratory analysis. By applying stepwise linear regression analyses to a mass of published data, DeKock and Franzidis ( 4 A ) obtained correlations which could be used for estimation of Hardgrove indices, calorific values, and ultimate analyses. Lau (IOA) in a statistical study of proximate analyses of samples from one mine correlated percent of ash with moisture content. volatiles, fixed carbon, and heat of combustion. Dmitriev e t al. ( 5 A ) used derivatography to determine moisture, ash, heat of combustion, and degree of metamorphism in a single coal sample. Examples were given. Moisture. Hall et al. ( 9 A ) reported on a neutron moisture meter for continuous monitoring of coal. A 1-curie americum-beryllium source was used. The fast neutrons thermalized by the hydrogen in the coal moisture were comAuthors have not been supplied with free reprints for distribution. Extra copies of the review issue may be obtained from Special issues Sales, ACS, 1155 16th St., N.W., Washington, DC 20036. Remit $4 for domestic U.S. orders: add $0.50 for additional postage tor foreign destinations.
pared to those thermalized by dry coal. Results agreed within 0.2% with results from conventional methods. Grieser and Klein ( 8 A ) proposed a method for the calibration of radiometric devices for the determination of moisture in coke and other bulk materials. In experimental work on a capacitance moisture meter, Protopopov and Bulycheva ( I 5 A ) found t h a t the instrument was extremely sensitive to changes in particle size. Ginzburg and Gatikh (6A) described an automatic method for the determination of the moisture content of peat briquets. They determined the correlation coefficient between the moisture content and capacitance and dielectric loss. Volatile. The release of volatiles from coal and char was studied by Chatterjee. He showed that when coal is subjected to rapid heating, the amount of volatiles depends mainly on the hydrogen to carbon ratio of the coal ( 2 A ) .He then determined the effect of a slow heating process (3A). Samples were preheated a t a rate of 4 "C/min from room temperature to 100, 200, 300, and 400 "C and the final temperature was maintained for one hour. These coals were then subjected to the standard volatile matter determination. The preheated coals contained more fixed carbon than the same coals subjected to just the standard method for volatile matter determination. Ash. A number of methods, all involving radiometric techniques, have been proposed. Goroshko and Lokshin ( 7 A ) found that the optimum sample moisture content was 25 f 290 when determining ash in coal by the gamma-ray absorptiometric method. Lokshin ( I I A ) claimed that since the sampling operation was eliminated, monitoring the ash by gamma-ray absorption gave more accurate values than those obtained by gravimetric methods. Papers by Rudanovskii et al. described the application of the radioisotopes selenium-75 and americium-241to the determination of ash. A gamma-ray absorption method employing americium-241 was recommended (26A). A method which depends on the measurement of forwardscattered selenium-75 radiation was also presented ( I 7 A ) . A N A L Y T I C A L CHEMISTRY, VOL. 47, NO. 5 , APRIL 1975
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The authors discussed the parameters and the sensitivity of the method. Mehrhoff ( 1 3 A ) described an automatic method using americium-241 for continuous ash determination in bituminous coal. Mechanical details were given and comparisons drawn between the radiometric method and conventional methods. Radioisotopes were also used by Volarovich e t al. (18A) t o determine the ash content of peat. The method is based on the correlation between the back scattered beta-radiation and the effective atomic number of the peat. Loska and Gorski (12A) determined ash in a n Upper Silesian coal by neutron activation analysis. The method depends upon the correlation between the total ash content and silica or silica plus alumina content. Advantages of the method are given. Radioisotope X-ray fluorescence is applicable t o the determination of ash in coal according to Clayton ( I A ) .
ULTIMATE AND SULFUR FORMS A method for determining the composition of fuels by analysis of the combustion gases was presented by Kasprzyk ( 8 B ) .It was proposed for routine control and could be used advantageously when fuel mixtures are burned. Carbon and Hydrogen. Fujiwara and Matsubara (5B) determined carbon and hydrogen on a number of coals using a Kohlmann analyzer. Optimum conditions were determined and results compared with those obtained using the Sheffield method. Carbon results agreed but hydrogen results using the Kohlmann analyzer were lower. Oxygen. A low-temperature oxygen plasma asher followed by NAA and DTA were used by Hasegawa e t al. ( 7 B ) in the determination of organic oxygen in coal. Total Surfur. Ahmed and Whalley ( I B ) developed a rapid method for the determination of total sulfur in coal. The sample was combusted in a n oxygen-flask and the p H of the hydrogen peroxide solution of the combustion gases determined. The method is claimed t o be sufficiently accurate for control analyses. However, a leaching step must be added for coals containing carbonates. The problems in the determination of sulfur in coal by X-ray fluorescence were discussed by Frigge ( 4 B ) . Both particle size and the chemical forms of the sulfur can affect the results. Ways of minimizing these problems were presented. By measuring the prompt gamma-rays produced by the interaction of thermal neutrons and coal, Parsignault et al. (12B) were able to determine the sulfur content of the coal within 2%. Californium-252 was the neutron source, and a mini-computer was used to analyze the gamma-ray spectra. Darlage et al. ( 3 B ) investigated the response of a flame photometric detector to the sulfur oxides produced by oxygen-flask combustion of coal. Eight coal samples were analyzed. The authors found the method to be simple, rapid, and reasonably quantitative. Forms of Sulfur. Schehl and Friedel (IOB)described an X-ray diffraction procedure for the quantitative determination of pyrite in coal. Computerized data processing allowed the analysis to be completed in approximately one hour. Electron emission spectroscopy was applied to the determination of forms of sulfur in coal. Schultz and Proctor ( I I B ) determined, by induced electron emission, the electron-binding energies of minerals found in coal. Correlations of chemical-shift data for minerals and organic sulfides with variations in structure and with sulfur signals in crude coals enabled the modes of occurrence of sulfur to be determined. Gohshi and Yanagase ( 6 B ) used high resolution X-ray 86R
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fluorescence to identify the chemical state of sulfur in coal. A 2-crystal spectrometer was used. The sulfur Kcu energy increased with increasing oxidation number. Baranskii e t al. ( 2 B ) studied methods for determining the various forms of organic sulfur in coals from the Donets and Irkutsk basins. Two main types of organic sulfur were present: primary sulfur from sulfur compounds in coal substances, and secondary sulfur from reactions of organic compounds with H2S in waters. Kuhn e t al. ( 9 B ) compared results for the forms of sulfur in coal as determined by the standard ASTM method with results using a reduction method using LiAlH4. Both methods produce reliable results but particle size is important in the LiAlH4 method.
PETROGRAPHY Current concepts of the structure of coals were reviewed by Ekaterinina et al. (6C). Microscopic, submicroscopic, supramolecular, and molecular structures are considered. Kessler (8C)presented a review and evaluation of the various methods of identifying and classifying macerals. The use of diamond reflectance standards for rapid petrographic coal analysis was discussed by Daniel (4C). Dobronravov (5C) investigated the relationship between the reflectance characteristics of vitrinites in polarized and unpolarized light and the angles between the bedding plane and the plane of polarization. Cook et al. ( 3 C ) discussed the causes of the triaxial character of anthracite vitrinites. A number of authors studied the application of coal petrography to coke making. Ammosov et al. ( I C ) published a review concerning the prediction of coke quality from petrographic features of coals. Glushchenko et al. (7C) presented empirical equations for predicting the yield of coking products as a function of the petrographic composition of the coal and of the volatile products yield. Kimura and Miyazu (9C)described the techniques of coal petrography and the application of petrography to coking technology. The effect of petrographic composition on the E P R spectra was the basis for a qualitative petrographic method proposed by Berger e t al. (2C). Fusinite has a more narrow and more intense E P R signal than vitrinite. Ash content and grain size also affect the intensity.
COKING PROCESSES AND COKE TESTING Carbonization. Lur'e e t al. ( 1 6 0 ) studied the influence of preliminary heat treatment and of grain size on the kinetics and coking capacities of certain coals. The effects of pressure on carbonization were examined by Tsukashima e t al. (350). Three types of Japanese coals were carbonized a t 400 and 500 "C a t pressures varying from 20 to 1000 Kg/cm2. Wieckowska et al. ( 3 6 0 ) investigated the low-temperature carbonization of coals in stationary and fluidized beds. The effects of grain size, carbonization temperature, heating rate, and residence time on the physicochemical properties of the carbonization products were determined. Schehl and Friedel ( 3 0 0 )studied, by X-ray analysis, the structure of cokes carbonized a t different temperatures. A blended coal was ground to -100 mesh, demineralized, and carbonized a t temperatures from 500 to 1000 "C. X-Ray diffraction was also used by Ibraev and Dzhamanbaev ( 1 2 0 ) to investigate the structural transformations of a brown coal carbonized a t 1000 to 2200 "C. Using pulse heating equipment, Mentser e t al. ( 1 9 0 ) were able to devolatilize coal a t rates comparable to combustion and gasification rates. Devolatilization curves for the bituminous coals were similar but curves from a subbituminous coal were very different. Heilpern ( 1 1 0 ) studied the degasification process of a
Elizabeth A. Hattman is a research chemist in Analytical Research and Services, Pittsburgh Energy Research Center. She received a B.S. degree from the University of Pittsburgh and later did graduate work there. Before joining the Pittsburgh Energy Research Center, she was an analytical chemist in the Pittsburgh Metallurgical Laboratory, Bureau of Mines. Most of her present work is concerned with the determination of trace metals in coal.
Hyrnan Schuitz, Supervisory Research Chemist, joined the Bureau of Mines staff in May 1971. He received his B.S. in chemistry at Brooklyn College in New York in 1956 and his Ph.D. in 1962 at The Pennsylvania State University. He is in charge of the Analytical Research and Services section of the Pittsburgh Energy Research Center. Prior to joining the Bureau, Dr. Schultz was engaged in industrial research in analytical chemistry.
John F. Smith is a Supervisory Chemist in Analytical Research and Services, Pittsburgh Energy Research Center. He received a B.S. degree from Juniata College, Huntingdon, PA. Most of his present work is concerned with the evaluation of liquid and gaseous products of energy related engineering processes.
number of coals and blends by derivatographic analysis. Statistical methods were applied by Slivinskaya et al. ( 3 1 0 ) to a study of the mechanism of coal pyrolysis. Experimental product yields from coals heated a t specified rates agreed with calculated data. Danilin et al. ( 4 0 ) derived equations to describe the correlation between changes in the pycnometric specific gravity of the coke, the density, and the temperature. A mathematical model was developed. Boteler and Boley (30) examined the partial devolatilization of coal in two entrained-bed carbonizers. Empirical equations were derived to predict carbonization temperature, air to coal ratio, devolatilization, char yield, and volatile content of the char. Kulik et al. ( 1 5 0 ) studied the semi-coking of lignite during repeated circulation of the vapor-gas mixture which acted as a heat-transfer agent. The effect of heating rate on yield and composition of products was investigated. The mechanisms of coal carbonization in the oven and of coke gasification in the blast furnace were discussed by Marsh ( I 7 0 ) . Correlation of fundamental knowledge with industrial usage, and an analysis of problems related to mechanisms in the plastic zone of the carbonizing system were topics of interest. Tikhonov ( 3 3 0 ) reviewed the possibilities of using less difficult and less time consuming control analyses during coke production.
A generalized equation was proposed by Gryaznov et al. ( 9 0 ) which could be used to determine the following coking process parameters: modulus of elasticity, specific shrinkage, thermal conductivity, coking time, and charge size. Lowering the pyrolysis temperature results in less sulfur in the coke oven gas according to Medvedev and Petropolskaya ( 1 8 0 ) . Kovalik et al. ( 1 4 0 ) tested the use of antifissurants t o improve the strength of cokes made from Illinois No. 6 coal and a high volatile coal from Kentucky. The coals were blended with fluidized-bed char and coke breeze before carbonization in the BM-AGA retort. Plastic Properties. Nesterenko e t al. ( 2 1 0 ) examined the characteristics of the liquid phase of a plastic coal mass. Factors which influenced yield and composition of the liquid phase included coal particle size and the presence of fusinite and vitrinite in the liquid phase. By selective extraction of the liquid phase, prepared by centrifugation, Nesterenko e t al. ( 2 2 0 ) obtained four chemical groups. The relative thermal stability and cakability of these groups were discussed. The effects of preliminary treatment of the coal with oxygen or hydrogen were also considered. Boiko et al. ( I D ) explored the change in coal macerals during plasticization. A rheological study of coals and coal charges was conducted by Geguchadze ( 6 0 ) . Indexes of flow, degree of swelling, rate of pyrolysis, and rate of flow were determined. Some properties could be used to compare coals of different cakability. The author also investigated the effect of pyrolysis time on the properties of coals in the plastic state ( 7 0 ) . The Gieseler apparatus was used by Kijewska ( 1 3 0 ) to study the plastic properties of blends of coal and semicoke. Research trends were discussed. Wu and Frederic ( 3 7 0 ) published linear correlations of parameters of coal composition and coal plasticity on coke strength. A structural theory of coal plasticity was suggested and applications of the correlation results discussed. Ruschev et al. ( 2 9 0 ) also obtained correlation coefficients among the various properties of thermally treated coals. Coke Strength. The influence of carbonizing conditions on the strength of coke was studied by Patrick et al. ( 2 3 0 ) . Two coal blends were carbonized under varying conditions. Strength indices were determined. The nature of the coal blend and not the carbonizing conditions was shown to have the greatest influence on coke strength. Muchnik et al. ( 2 0 0 ) and Pokhvisnev et al. ( 2 4 0 ) developed drum tests to establish the strength and wearing properties of coke. An algorithm for predicting coke quality, as measured by the micum 40 test, from known coal charge parameters was derived by Borkowski ( 2 0j. The best correlation was found to be between the micum 40 test and the Giesler parameters. Reinhorn ( 2 8 0 ) proposed the use of the hot-resistance test developed by Barbu et al. (1967) for the testing of furnace coke and various formed products. The author claimed that the method was more sensitive and more reproducible than the micum test. Glushchenko et al. (80)developed analytical equations to show the correlations between coke size and strength and the properties of the coal. Reactivity. The theoretical considerations concerned with measurement of coke reactivity were discussed by Reeve (2601, and Reeve et al. ( 2 7 0 ) compared three test methods for reactivity measurement. All three methods gave acceptable values on a series of eight cokes. Fassotte and Saussez ( 5 0 ) used thermogravimetric analANALYTICAL CHEMISTRY. VOL. 47,
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ysis to determine the reactivity of preformed and ordinary cokes. They compared the reactivity of a number of formed cokes and metallurgical cokes and investigated the mechanisms involved. The many factors which affect the reactivity and electrical restivity of non-metallurgical cokes were studied by Gryaznov et al. ( 1 0 0 ) . Slomska ( 3 2 0 ) presented a new method for the interpretation of coke reactivity which depended on graphical interpretation. Density. Toda and Toyoda ( 3 4 0 ) compared the densities measured with methanol and with helium for five Japanese coals carbonized a t various temperatures. The roles of the intra- and inter-crystallite pores were discussed. The true density of coke was measured by Protasenya et al. ( 2 5 0 )using a modification of the method and apparatus proposed by Y. Y. Bobyrako in 1965.
INORGANIC CONSTITUENTS IN COAL, COKE, AND ASH Mineral Matter. The heat produced during combustion of coal alters the minerals present. The problem of determining “mineral matter” as opposed to “ash content” has been approached from a number of angles. Formulas for estimation have been proposed but are not completely satisfactory because of wide variation in coal composition. Radiofrequency oxidation techniques have been used by a number of authors. Frazer and Belcher (20E) tested a lowtemperature (-150 “C) radiofrequency technique and found superior retention of carbonates and sulfide minerals along with shorter time requirements and wider applicability when compared with air oxidation. A low-temperature asher was used by Rao and Gluskoter ( 5 I E ) to obtain the mineral matter from 65 Illinois coal samples. Chemical, microscopic, and X-ray diffraction analyses were subsequently performed. O’Gorman and Walker (48E) studied the thermal behavior of mineral fractions separated from four coals by low-temperature ashing. Thermogravimetric and derivative thermogravimetric analysis methods were used. Mukherjee et al. (43E) also used thermogravimetric and derivative thermogravimetric methods to identify and estimate clay minerals associated with Indian coals. Treatment with hydrogen peroxide was proposed by Nalwalk and Friedel ( & E ) as a means of removing organic matter in coal. Pyrite was partially oxidized but clay minerals and other hydrates were not decomposed or dehydrated. Fujimori et al. (25E) compared the pressometric and gravimetric methods for the determination of carbon dioxide in coal. No significant difference was found between the results of the two methods. Coal Dust Monitoring and Analysis. Increased awareness of the health hazards of coal mine dust has spurred research on monitoring and analysis. Portable monitors were developed by Schehl (%E), by Lapple and Schadt (36E), and by Lilienfield and Dulchinos (39E). Breuer ( 6 E ) reviewed the development of gravimetric dust sampling methods in the West German coal mining industry. The term “Respirable Dust Index” was proposed by Thakur and Sinha (62E)to express the difference in the yield of respirable dusts from different coals. Corn et al. (IOE, I I E ) published articles which discussed the physical and chemical properties of respirable coal dusts. The composition of coal mine dust was investigated by Kizel’shtein ( 3 5 3 ) . Higher concentrations of pyrite, quartz, and carbonates were found in the dust as compared to the concentration of these compounds in the coal seam. Rhodes and Taylor (52E) investigated a number of sophisticated techniques for the rapid determination of major el88R
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ements in mine dust. The equipment was able to be truckmounted for field operation. Infrared methods for the determination of quartz in coal dust were reported by Goldberg and Jacobson (26E)and by Larsen et al. (37E). Hurley and White (29E) and Bochenin ( 4 E ) presented X-ray techniques for the above determination. Majumdar (42E) reviewed chemical methods for determining free silica, and Freedman and Sharkey ( 2 I E ) reviewed recent advances in the analysis of respirable coal dust for free silica, trace elements, and organic constituents. Major and Minor Elements. Karacki and Corcoran ( 3 I E ) used a high-temperature argon plasma emission excitation source to analyze coal ash dissolved by lithium metaborate fusion. Determinations of S, Al, Fe, Ti, P, Ca, Mg, Na, and K were completed in 1-2 hours. Popov et al. (5OE) studied buffer mixtures used in the determination of Si, Fe, Al, Ca, and Mg in peat by emission spectrometry. No preliminary ashing was used. A buffer composed of 5 parts C powder, 3 parts dithizone, and 2 parts BaC12 was recommended. A rapid titrimetric method for the determination of calcium oxide and magnesium oxide in ash was developed by Novitskii and Ivanova (47E).Preliminary separation of silica and aluminum, iron, and titanium oxides was not necessary. Fujimori et al. (22E) determined phosphorus in coal and coke by a wet oxidation technique and by the oxygen flask method and suggested modifications of the procedures (23E). They found that phosphorus was lost during dry ashing (24E). Trace Elements. Although only trace amounts of many elements may be present, because of the large tonnages of coal consumed each year, the environmental effect of the emission of trace elements is a cause for concern. Davis, in a national inventory of sources and emissions for 1969, attributes about 26% of total barium emission (12E),about 43% of boron emissions (13E),and about 65% of selenium emissions (15E) to coal combustion. Emissions of copper (14E) and zinc (16E) were considered “significant”. Trace metal pollution in urban air and concentration ranges in certain fuels and emission sources were reviewed by Lee and von Lehmden (38E). Natusch et al. (45E) found that the toxic trace elements, arsenic, antimony, cadmium, lead, selenium, and thallium, were most concentrated in the respirable size particles emitted during combustion. Toca et al. (63E) also found the largest amount of cadmium and lead in the respirable size fractions. Trace element mass balances around a coal-fired steam plant were investigated by Bolton et al. ( 5 E ) . Mercury mass balances were determined by Kalb and Baldeck (30E) and by Billings et al. (2E). The fate of some trace elements during coal pretreatment and combustion was discussed by Schultz et al. (57E). Attari ( I E ) investigated lab methods for the determination of Sb, As, Be, Cd, Cr, Pb, Hg, Ni, Se, Te, and V and applied these methods to coal and solid effluents from the various stages of a coal gasification pilot plant. Capes et al. ( 8 E )studied the rejection of trace metals from coal during beneficiation by agglomeration. A comprehensive report on the occurrence and distribution of potentially volatile trace elements in coal was published by Ruch et al. (53E).Procedures used are described and results from the various procedures are compared. Pollock (49E) discussed the determination of 23 trace elements in coal. Six elements were determined by mass spectrometry and 17 by wet chemistry. An inter-laboratory comparison study on the determina-
tion of trace elements in fuel was conducted by von Lehmden et al. (65E).Nine laboratories were asked to determine the concentration of 28 elements in a sample of coal, fly ash, fuel oil, and gasoline. Analytical techniques used included atomic absorption, X-ray fluorescence, anodic stripping voltammetry, optical emission spectrometry, neutron activation analysis, and spark source mass spectrometry. The large variations in reported values for many of the elements show the need for standard reference materials for evaluating methods and for quality control. Spark source mass spectrometry has been extensively used for the determination of trace elements in coal. Brown et al. ( 7 E ) reviewed applications of this technique to the analysis of coal, fly ash, respirable coal dust, and lung tissue. Guidoboni ( 2 7 E ) compared results from spark source determinations of Mn, Ni, Cr, V, Cu, and Zn with atomic absorption values for the same samples. The relative standard deviations ranged from 6-15% for mass spectrometry and 2-3% by atomic absorption. As part of a respirable mine dust research program, Kessler e t al. ( 3 3 E ) made semi-quantitative determinations of 64 elements in 1 2 samples of coals of varying rank. Isotope dilution mass spectrometry was used by Carter e t al. ( 9 E ) to determine trace metals in fuels. Both spark source and thermal emission mass spectrometric methods were developed. A neutron activation method was developed by Block and Dams ( 3 E ) for the determination of over 40 elements in coal. Two neutron irradiations and 3-5 gamma-spectrometric measurements were employed. Sheibley ( 5 9 E ) also used neutron activation for coal trace element analyses. Two aliquots were irradiated and a total of 5 counts were taken. Kuhn et al. ( 3 4 E )developed X-ray fluorescence methods for the determination of a number of minor and trace elements in whole coal and in coal ash. An X-ray method for trace element determination using 40-MeV 0 ions to induce fluorescence in infinitely thick samples of coal ash and other materials was investigated by Shabason et al. (58E). Arsenic. Santoliquido (54E) used inorganic ion exchangers to separate As for its determination following neutron activation. The separation using acid A1203 or hydrated MnOz was shorter than the tribromide distillation and the results were comparable. Beryllium. A colorimetric procedure for the determination of Be in coal and coke was proposed by Vasil’eva and Vekhov (64E). The powdered sample is mixed with 10 times its weight of sodium carbonate, ashed, and fused. Be is isolated as the phosphate and determined with Beryllon
P. Chromium. Dittrich and Liesch ( I 7 E ) determined Cr in electrode cokes by atomic absorption spectrophotometry. Results ranged between 0.1 to 2 ppm. The effects of H2SO4 and KHS04 were discussed. Gallium. A neutron activation method was developed by Santoliquido and Ruch ( 5 5 E ) .After low temperature ashing, separation of Ga from As and Sr, and irradiation, the sample was fused and Ga separated and counted. The possible interference of germanium was investigated. Losev et al. ( 4 I E )studied the evolution of gallium during a carbonization of western Donets basin coals. About two thirds of the initial gallium remained in the coke and about one quarter was recovered from the gas. Widawska-Kusmierska (67E) investigated the occurrence of gallium in Polish bituminous coals. A total of 2852 samples were analyzed by spectrographic and atomic absorption methods. Germanium. A photometric method for the determina-
tion of trace amounts of germanium was developed by Finkel’steinaite and Burskiene ( 1 9 E )and applied to the determination of germanium in coal. Hydroxy-hydroquinone Pink was the colorimetric agent. Mercury. Kennedy e t al. ( 3 2 E ) determined mercury in coal and lake sediments using neutron activation followed by hot tube combustion or volatilization to separate the mercury. Neutron activation was also used by Weaver (66E)to determine mercury and selenium in coal. An Ortic Low Energy Photon Detector and an N.D. 2200 Multichannel Analyzer were used. The method requires no chemical separations. The combustion procedure previously developed by Baily and Lo has been modified by Lo and Bush (40E) to permit more rapid and more precise analyses. By initiating the combustion in air and then switching to oxygen, ignition is much milder. Huffman e t al. (28E) determined mercury in geologic materials by flameless atomic absorption. After wet oxidation of the samples, the mercury was reduced, aerated, and collected on a silver screen. The silver screen was heated and the mercury measured in a spectrophotometer. Rhenium. Rhenium in coal, oil shale, and rock was determined by neutron activation. Nikanorov et al. (46E) separated the irradiated rhenium and carrier by extraction. The sensitivity of the determination was 1 X and the error approximately 10%. Scandium. A photometric method for the determination of scandium in coals was studied by Suvorovskaya and Shmarinova ( 6 I E ) . The absorbance of the Rhodamine B complex was measured. Interference by ytterbium, europium, gadolinium, and samarium was found. Selenium. Sidel’nikova (60E) used wet oxidation followed by extraction of the selenium complex of 2,3-diaminonaphthalene into cyclohexane to determine selenium in coalified plant residues.
STANDARD METHODS The American Society for Testing and Materials through its Technical Committee D-5, develops and standardizes test procedures for coal and coke. These standards ( I F ) are published annually. Standards adopted or revised during this review period include the following: Ash in the Analysis Sample of Coal and Coke (D3174-73), Calculating Coal and Coke Analyses from As Determined to Different Bases (D3180-74), Carbon and Hydrogen in the Analysis Sample of Coal and Coke (D3178-73), Equilibrium Moisture of Coal a t 96 to 97 Percent Relative Humidity and 30 OC (D1412-74), Gross Calorific Value of Solid Fuel by the Isothermal-Jacket Bomb Calorimeter (D3286-73), Moisture in the Analysis Sample of Coal and Coke (D3173-73), Nitrogen in the Analysis Sample of Coal and Coke (D3179-73), Proximate Analysis of Coal and Coke (D3172-73), Total Sulfur in the Analysis Sample of Coal and Coke (D3177731, Ultimate Analysis of Coal and Coke (D3176-74), Volatile Matter in the Analysis Sample of Coal and Coke (D3175-731, and Specific Gravity and Porosity of Lump Coke (D167-73). Committee D-5 also recommends approval of certain standards by the American National Standards Institute (ANSI) as national standards for international participation.
MISCELLANEOUS Vassamillet (13G) examined medium rank coals with a scanning electron microscope. He found iron present as small dense particles, thus confirming results of earlier Mossbauer spectral analyses. ANALYTICAL CHEMISTRY, VOL. 47, NO. 5, APRIL 1975
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X-Ray diffraction was used by Artemov and Kovalev ( 3 G )to investigate the supermolecular structure of coals of various grades. The different metamorphic grades exhibited different supermolecular structures. The nature of electron paramagnetic resonance signals from coals was studied by Tyutyunnikov et al. ( I I G ) . Measurements were made a t room temperature in air and a t low pressure. With the exception of bituminous coal, the intensity of the signals increased with rank. Gan et al. ( 7 G ) investigated the nature of the porosity of American coals. Gas absorption, helium, and mercury displacement and mercury porosimetry techniques were used. Toda and Toyoda (10G) derived a quantitative relationship between the micropore volume as determined by carbon dioxide adsorption, and the moisture content for a series of coals and their carbonized products. Coals with less than 81%carbon did not conform. Agroskin ( 2 G ) discussed the results of heat capacity and thermal conductivity measurements for cokes and for different rank coals. The explosibility of coal dust was studied by Sliz and Lebecki (9G). The apparatus used was adapted from a Bureau of Mines design. Achari and Sengupta ( I G ) established a functional relationship between the relative flammability of dust and its ash content. The effect of moisture on tests of coal self-heating properties was investigated by Bylo and Polchlopek (5G). They found that standard moisture conditions were necessary for best results. Kissell et al. ( 8 G ) proposed a direct method for determining the methane content of coal beds. The results could be used to give an approximation of the total gas emission from a prospective mine. Berger et al. ( 4 G ) reviewed stack sampling procedures for sulfur and nitrogen oxides in fossil fuel combustion. A number of unique applications of a metallograph to coal research were proposed by Fairbanks (6G).The author discussed the use of the instrument in studies of low temperature oxidation of coal, coal hardness, and the magnetic separation of pyrite from coal.
GASEOUS FUELS The Review of Gaseous Fuels covers the following areas of interest: General Reviews, Gas Chromatography, Sulfur Compounds, Water Vapor, Potentiometric and Colorimetric, Infrared and Mass Spectrometry, Sampling, Oxides of Nitrogen, Miscellaneous, and Standards. Methods, techniques, procedures, apparatus, instrumentation, and fabrication of equipment that have been used in the determination and analysis of fuel gases and impurities that are an integral part of fuel gases are included in the review.
GENERAL REVIEWS Reviews included Chromatography in the Petroleum Industry by Camin and Raymond ( 5 H ) ,Some Aspects of Injection of Large Samples in Gas Chromatograph by Harris ( 9 H ) ,Emerging Technologies in Chromatography Automation by Hettinger and Hubbard ( I O H ) , Gas and Liquid Chromatography-State of the Art ( 1 7 H ) , and Sampling Techniques in Chromatography ( 1 8 H ) by Karasek, Automated Gas Chromatographic Analysis of Sulfur Pollutants by Pecsar and Hartmann ( 2 4 H ) , Review and Statistical Analysis of Stack Sampling Procedures for the Sulfur and Nitrogen Oxides in Fossil Fuel Combustion by Berger et al. (ZH), Current Instrumentation for Continuous Monitoring for Sulfur Dioxide by Hollowell et al. ( 1 3 H ) ,Ambient Air Monitoring of Gaseous Pollutants by Coloff et al. ( 6 H ) ,Experimental Measurement Methods Based on Gas Phase Chemiluminescence by Fontijn (8H), Analytical Methods 90R
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for Atmospheric Oxidants Measurements by Hodgeson ( I I H ) ,Methods of Analysis for Oxides of Nitrogen by Allen ( I H ) , Comparison of Hydrogen Sulfide Analysis Techniques by Bethea ( 3 H ) ,Gas Chromatography-Mass Spectrometry by Brooks ( 4 H ) , Combining the Gas Chromatograph and the Mass Spectrometer by Hogg ( I Z H ) , Modern Thermal Conductivity Detectors for Gas Chromatographs by Johns and Stapp ( 1 6 H ) ,Principles of Detection by Keller ( 1 9 H ) , Increased Gas Chromatograph Reliability for Control by Martin (21H), Quantitation of Thermal Conductivity Detectars by Rosie and Barry ( 1 4 H ) , Near Infrared by Jansson and Hunt ( 1 5 H ) , New Techniques for Flammable Gas Detection by Nesvig (ZZH), Chromatographic Support in Gas Chromatography by Ottenstein (23H),Introduction to Analytical Methods by Richardson and Peterson (25H), Petroleum by King e t al. (20H), Air Analysis-Recent Instrumentation Studies and Survey Experience by Dennison et al. ( 7 H ) .
GAS CHROMATOGRAPHY Gas chromatography continues to be one of the most widely used techniques for the detailed analysis of gaseous fuels. Improvements continue to be made in instrumentation, methods, and applications. This review includes articles and books on procedures, analytical techniques, applications, column packings, and usage. Bollman et al. (61) used a carbon molecular sieve column in parallel with a conventional molecular sieve column to determine carbon dioxide, hydrogen sulfide, sulfur dioxide, ethane, and propane in kiln and furnace gases. Determination of carbon dioxide in the parts-per-million range by conversion to CH4 and detection with a flame ionization detector is described by Williams et ai. (511). Apparatus and methods for separating, concentrating, detecting, and measuring trace gases using a plasma chromatograph are described by Cohen et al. (101). A gas chromatographic method for analyzing mixtures of hydrocarbon and inorganic gases utilizing both thermal conductivity and flame ionization detectors is presented by Kim and Douglas (291). Lang and Freedman (341) perform a three-minute gas chromatographic analysis of the main constituents of mine atmospheres using a split gas sample and 2 columns in separate chromatographs. An improved analysis of natural gas using three advanced gas chromatographic methods is presented by Purcell and Gilson (431).Lamb et al. (321) describe a method for the analysis of stack and exhaust gases and discuss applications to the study of the catalytic reduction of NO,. Nand and Sarkar (391) have developed a one-step analysis technique for a mixture of permanent gases and light hydrocarbons by gas chromatography without subambient temperature programming. Kim (301) presents the composition, as determined by gas chromatography, of samples obtained directly from a coal bed during the drilling of horizontal and vertical boreholes. Use of chemical reaction methods for the preparation of standard mixtures for qualitative analysis by gas chromatography is discussed by Berezkin et al. (31). Cheder and Cram (81) discuss digitization errors in the measurement of statistical moments of chromatographic peaks. Chilicote and Scott (91) present a discussion of mathematical analyses of normalization techniques used in chromatography. Cooke ( I 21) evaluates computer analysis of asymmetric peaks in gas chromatography. Longbottom (351) suggests the use of a programmable calculator with plotting capabilities to assist in gas chromatographic computations. Schatzki (461)discusses the manual integration of distorted and multiple gas chromatographic peaks and proposes a simple algorithm for deconvoluting and integrating these peaks.
A study of sources of error in chromatographic analysis is presented by Goedert and Guiochon and includes: Effect of Sampling Parameters on the Accuracy of Numerical Measurements (151), Simulation of the Process of Data Acquisition and Calculations (161),Random Errors Made During (Chromatographic) Peak Area Measurements for Concentration Determinations by the Internal Standards Method (171), Systematic Errors on the Determination of Retention Times (181), Effect of Random Noise on the Precision and Accuracy of Measurements of Peak Area and Retention Time (191).Mignano et al. (381) discuss the elimination of spurious peaks in subambient temperature programmed gas chromatographic analysis of fixed gases by use of a thermally regenerable, cryogenic trap. Oppegaard (401) presents problems and improvements in the use of septum-syringe-injector application in gas chromatography. Gas density balance calibration techniques as applied to relative response factors for thermal conductivity detectors are evaluated by Vermont and Guillemin (491). Blondfield and Seibel (51) describe an automatic Sampling and sample injection system for gas chromatography. Karasek (271) presents guidelines on the proper choice of sampling devices and techniques to ensure the output of accurate data from chromatographs. Rasmussen (451) has developed a “syringe gripper” device for improved injection of high pressure gas samples. Alekseeva and Aerov (11) discuss the effect of natural convection in chromatographic columns based on the differences in retention times and peak widths. Goodley and Gordon (201) propose the use of the economical fluidized drier for the preparation of packing material. Markey and Simons (361) present an improved polyimide ferrule which provides a removable union between glass columns and other fixed glass lines. Ottenstein et al. (411) and Ottenstein (421) present a discussion on chromatographic support materials to assist in preparation of more effective columns. Portable, self-contained gas chromatographs have been developed by Debbrecht and Nee1 (1411, Josias et al. (261), Matson and Goings (371),and Stevens et al. (481).The accuracy and precision of several portable gas detectors for assaying CO, CO2, 0 2 , and CHI were studied by Carroll and Armstrong (71). Gupta et al. (211) discuss the response of the flame ionization detector to nitrogen and oxygen. Hoberecht and Klimowski (231) describe an inexpensive, fully automated gas chromatographic data system which injects samples, selects and applies computational methods appropriate to each sample, and issues a printed report. Hettinger et al. (221) present a new computing integrator for gas chromatography which is a firmware-driven digital system by which 4 or less chromatographs can be automated simultaneously. Jordan (251) discusses a minicomputer system with a 4K core which services gas chromatographs and performs 5 analyses simultaneously. Landowne et al. (331) describe a computerized system for a multiple gas chromatographic laboratory where simultaneous operation of all chromatographs is possible in real time even while the computer performs other functions. Books which have been written on gas chromatography in this reporting period include: “Gas Chromatographic Analysis of Trace Impurities” by Berezkin and Tatarinskii (41) deals with the analysis for trace compounds, not only in air, but in other compounds. Basic methods of gas chromatography are also discussed. “Gas Chromatography Applications” (21)covers a wide variety of applications selected as being of greatest interest to the analyst and research scientists. “Gas Analysis by Gas Chromatography” by Jeffery and Kipping (241) is a revision of a volume first pub-
lished in 1964. “Gas Chromatography” by Simpson (471) includes theory and practical details of gas chromatography techniques. “Chromatographic Systems-Maintenance and Troubleshooting” by Walker et al. (501) bridges the gap between the chromatographer and the service engineer. “Advances in Chromatography 1973” by Zlatkis (521) includes discussions of theory, columns, detectors, quantitation, and applications. Zweig and Sherma (531) compiled the “Handbook of Chromatography”, Volumes I and 11, which give the essentials for analyzing over 12,000 compounds as published in the last 25 years. A new monograph titled “An Introduction to Separation Science” was written by Karger et al. (281). Purnell (441) edited Volume I1 of “New Developments in Gas Chromatography”, Knapman and Maggs (311) edited “Gas and Liquid Chromatography Abstracts 1972”, David (131) published “Gas Chromatographic Detectors”, and “Identification of Organic Compounds With the Aid of Gas Chromatography” is presented by Crippen (121).
SULFUR COMPOUNDS Kimbell ( I 7 5 ) has developed a total sulfur analyzer which can be adapted for the analysis of sulfur in solid or gaseous samples. Kniebes et al. (195) use gas chromatography results for reporting direct odor levels by separating and measuring sulfur compounds in natural gas. Carbon disulfide vapor in air a t concentrations 1 4 0 ppm V/V was determined using a modified colorimetric field test method developed by Hunt et al. ( 1 5 5 ) . The pararosaniline reference method for the determination of sulfur dioxide in the atmosphere was evaluated by Blacker et al. ( 3 5 ) using a continuous conductivity instrument. Bruner e t al. ( 5 5 ) couple permeation and exponential dilution methods for use in gas chromatographic trace analysis for sulfur dioxide. Carlson and Black ( 6 5 ) present a method for rapid analysis of lead dioxide candles exposed to ambient air containing sulfurous pollutants using atomic absorption spectrophotometry. This method should be applicable to other types of PbO2 samplers, such as sulfation plates. Coloff et al. ( 7 5 ) review the operational theory and applications of reference analytical methods presently used for the ambient air monitoring of the five gaseous pollutants: SOs, CO, photochemical oxidants, hydrocarbons, and NO2. Instruments based on colorimetry, conductivity, coulometry, and flame photometry are also discussed. Dahms (85) has developed an electrolytic cell with a silver-phosphate buffer electrolyte and an SOZ-permeable membrane. The cell can be used to monitor sulfur dioxide pollution in air and to analyze combustion products in the determination of sulfur in organic compounds. Wet-chemical methods for the determination of oxides of sulfur from stationary sources were evaluated by Driscoll et al. (95). Frechette and Fasching (105) have developed a new system for the detection and measurement of sulfur dioxide using a coated piezoelectric crystal. The device is rugged, portable, inexpensive, and should lend itself easily to automation. Galeano e t al. ( 1 2 5 )discuss the determination of sulfur oxides in the flue gases of the pulping processes. Hems and Adams (145) have developed an automated gas chromatography method for the determination of nitrogen, oxygen, and sulfur dioxide. Sulfur dioxide concentrations in the range of 200 ppm-10 vol.% and oxygen in the range of 0.1-25% are detected within 7 minutes. Liang et al. (225) present an evaluation of the effectiveness of the lead peroxide method for atmospheric monitoring of sulfur dioxide. A method of collection and determination of sulfur dioxide incorporating permeation and the West-Gaeke procedure is described by Reiszner and West ( 2 8 5 ) .Saltzman (305) discusses per-
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meation tubes as primary gaseous standards. Liquified gases such as SO2 are sealed in Teflon tubes and permeate through the walls a t constant rates. Salzano et al. (325) report on an electrochemical cell for the determination of SO2 and so3 in air or oxygen-containing gases. Syty (345) has developed a method for the determination of sulfur dioxide by ultraviolet absorption spectrometry using a 15cm long flowthrough cell with quartz end windows. Potentiometric determination of sulfur dioxide in flue gases using an ion selective lead electrode has been developed by Young et al. (375). Klauber (185) describes a method to image normally invisible SO2 plumes on photographic film using the sun’s ultraviolet light in the absorption band of SO2 near 300 nm. Krueger (215) uses a potentiometric gassensing electrode to measure sulfur dioxide in absorbing solutions from lamp sulfur determinations. Scarano et al. (335) describe a method for the preparation of gaseous standard solutions of sulfur dioxide by passing an inert gas through suitable liquid solutions. West et al. (365) present a reliable method for the determination of sulfuric acid aerosols in the atmosphere using a simple technique and inexpensive equipment. Determination of SO2 by anodic oxidation on lead dioxide electrodes is described by BBlanger (15).Reiszner (275) evaluates the average concentration of sulfur dioxide in air by permeation through polymer membranes and spectrophotometric determination. Frechette et al. (115) evaluate substrates for use on a piezoelectric detector for sulfur dioxide. Bethea (25) compares hydrogen sulfide analysis techniques. Paper tapes, wet chemical methods, infrared spectrometry, and gas chromatography are included in the evaluation. Pertinent details are included for each method. Bollman and Mortimore ( 4 5 ) use a carbon molecular sieve column for the determination of hydrogen suifide, sulfur dioxide, ethane, propane, and carbon dioxide. Gas detector tube systems for the determination of hydrogen sulfide in the concentration ranges of 5-50 ppm were evaluated by Johnson (165) and results are presented. Kremer and Spicer (205) describe a gas chromatographic single pass system for the separation of hydrogen sulfide, carbonyl sulfide, and higher sulfur compounds. An assessment of impregnated paper tape methods for the determination of hydrogen sulfide in air has been conducted by Natusch et al. (245). A sensitive method for collection of atmospheric hydrogen sulfide using a AgN03 impregnated filter is described by Natusch et al. (255).Ronkainen et al. (295) report a gas chromatographic method for the analysis of volatile sulfur compounds. Saltzman and Hunt (315) describe a photometric analyzer system for monitoring and control of the hydrogen sulfide/sulfur dioxide ratio in sulfur recovery plants. Trace determination of hydrogen sulfide and sulfur dioxide by rapid, on-line, gas chromatography is presented by Tourres (355). Greer and Bydalek (135) discuss the response characterization of the Melpar flame photometric detector for hydrogen sulfide and sulfur dioxide. Detection of sulfur dioxide and carbon dioxide with a heterodyne radiometer shows sensitivity adequate for remote stack monitoring and other sensing applications according to hlenzies (235).An ambient and source sulfur dioxide detector based on a fluorescence method is described by Okabe et al. (265).
WATER VAPOR Gravimetric and volumetric techniques for measuring sorption of water by ion-exchange resin spheres are discussed by La1 and Douglas ( 3 K ) .Dew point concentrations of very dilute gas mixtures a t low temperatures and elevated pressures can be predicted by a method developed by Chen et al. ( 2 K ) . Capuano ( I K ) determined moisture in 92R
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gases by measuring the current needed to electrolyze the moisture absorbed on a hydroscopic film. A membrane separator for removing water vapor from carrier gas streams of a gas analyzer is described by Varian Associates ( 5 K ) .Scott ( 4 K ) describes an apparatus for producing gaseous moisture calibration standards.
POTENTIOMETRIC AND COLORIMETRIC Bailey and Bishop ( 1 L ) describe a coulometric determination of sulfur dioxide using differential electrolytic potentiometry for end-point location. An instrument capable of automatic continuous chromatographic coulometric analysis of sulfur compounds in stack gases has been developed by Robertus and Schaer ( 3 L ) .The instrument is portable and uses a chromatograph column for separation and a bromine titration cell for detection of sulfur compounds. Williams and Carritt ( 4 L ) describe a technique which enables the quantitative introduction of either oxygen or nitrogen into the sample stream of a gas chromatograph. Coulometric generation of these gases permits calibration of a thermal conductivity detector for a continuous range of sample sizes. Lambert and Wiens ( 2 L ) report on an induced colorimetric method for carbon monoxide in which a soluble (crystal violet) colored compound is formed in aqueous solution a t room temperature.
MASS SPECTROMETRY AND IR Davis ( 5 M ) describes an apparatus and method for the mass spectrometric analysis of impurities in air and other gases. Photoionization mass spectrometry was evaluated for the analysis of ppm levels of gases in air by Driscoll and Warneck ( 6 M ) . Emerson et al. ( 7 M ) report on the mass spectrometric detection of impurities in helium, and Meinders ( 1 8 M ) on the mass spectrometric determination of impurities in hydrogen. Pebler and Hickam (21M) analyze trace impurities in helium, hydrogen, argonhitrogen mixtures, and high pressure steam by application of a cryogenic freeze-out technique to extend the sensitivity of mass spectrometric analysis into the sub-ppm range. A freezeout-thermal analysis mass spectrometric technique is used by Schubert (23M) for identifying trace impurities in gas samples. A total-effluent gas chromatograph-mass spectrometry system suitable for a wide range from low molecular weight gases to high molecular weight steroids is proposed by Henderson and Steel ( 1 2 M ) . Seidenberg and Hobbs (24M) describe a method and apparatus for determining the contents of contained gas samples for analysis with a gas chromatograph and/or mass spectrometer without permanently damaging the container. Mieure et al. ( 1 9 M ) propose increasing gas chromatograph and/or mass spectrometer usage by interfacing a second gas chromatograph and directing the effluent from either gas chromatograph into the mass spectrometer by miniature valving. Various interface systems for gas chromatograph-mass spectrometer coupling are discussed by Freedman ( 9 M ) . Gilby and Gaglione (IOM) describe a condensation technique for enrichment of gas chromatographic effluents followed by subsequent vaporization for spectrophotometric analysis. Chan et al. ( 3 M )analyze the principles of remote sensing and characterization of stack gases by infrared spectroscopy. C2H4, COS, CO, and CH4 C2He are determined using a non-dispersive infrared analyzer as presented by Dailey ( 4 M ) . Hanst et al. ( 1 I M ) use infrared spectroscopy with the scanning Michelson interferometer to measure the significant gaseous air pollutants at concentrations
