11
V O L U M E 2 2 , NO. 1, J A N U A R Y 1 9 5 0 (197) Pirlot, G., A n a l . Chem. Acta, 2, 744 (1948). (198) Pitser, K. S., and Weltner, W., Jr., J . Am. Chem. SOC., 71, 2842 (1949). (199) Plyler, E. K., J . Chem. Phys., 17, 218 (1949). (200) Plyler, E. K., and Acquista, N.,J . Research Natl. BUT.Standards, 43, 37 (1949). (201) Posey, L. R., Jr., and Barker, E. F., J . Chem. Phys., 17, 182 (1949). (202) Potter, R. L., Ibid., 17, 957 (1949). (203) Price, W.C., Ibid., 17, 1044 (1949). (204) .Price, W.C., Longuet-Higgins, H. C., Rice, B., and Young, T . F.. Ibid..17. 217 (1949). Price, W.C., and Tetlow, K. S., Ibid., 16, 1157 (1948). Prikhotko, A. F., J . Exptl. Theoret. Phys. (U.S.S.R.), 19, 383 (1949). Ramsay, D. A4., J . Chem. Phys., 17, 666 (1949). Randall, Fowler, Fuson, and Dangl, “Infrared Determination of Organic Structures,” New York, D. Van K’ostrand Co., 1949. Rasmussen, R. S., and Brattain, R. R., J . Am. Chern. SOC., 71, 1073 (1949). Rasmussen, R. S . , Tunnicliff, D. D., and Brattain, R. R., Ibid., 71, 1068 (1949). Rhodes, K. B., and Bell, E. E., P h y s . Rez., 76, 1273 (1949). Richard*, R. E., and Burton, W, R., Trans. Faraday SOC., 45, 874 (1949). Richards, R. E., and Thompson, H. W., J . Chem. SOC.,1949, 124. Richaids, R. E., and Thompson, H. IT., Proc. Roy. SOC., A195, 1 (1948). Roberts, J. D., Urbanek, L., and Armstrong, R., J . Am. Chem. Soc., 71, 3049 (1949). Roberts. J. S.. and Sswarc, M., J . Chem. Phys., 16, 981 (1948). Saksena, B., and Narain, H., Sature, 164, 583 (1949). Saunders, R. A,, and Smith, D. C., J . Applied Phys., 20, 953 (1949). --, \ - -
Schreiber, K. C., ASAL.CHEDI.,21, 1168 (1949). Scott, D. W.,Oliver, G. D., Gross, M. E., Hubbard, W.N., J . Am. Chem. SOC.,71, 2293 (1949). and Huffman, H. M., Semniens, E., Y a t u r e , 163, 371 (1949). Sheline, R. IC, and Weigl, J. W.,J . Chem. Phys., 17, 747 (1949). Sheppard, N., Ibid., 17, 74 (1949). Ibid., p. 79. Ibid., p. 455.
Sheppard, X., Trans. Faraday SOC.,45, 693 (1949). Sheooard. N.. and Sutherland, G. B. B. M., Proc. Rou. SOC., Ai96, 195 (1949). Sheppard, K,, and Seass, G. J., J . Chem. P h y s . , 17,86 (1949) Silverman, S.,J . Optical SOC.Am., 38, 989 (1948). Ibid.,39, 275 (1949). Silverman, S., and Herman, R. C., Ibid., 39 216 (1949). Simanouti, T., J. Chem. Phys., 17, 734 (1949). Ibid.,p. 845. Simpson, D. M., and Sutherland, G. B. B. M., Proc. Roy. SOC., A199, 169 (1949). Smith. L. G., J . Chem. Phys., 17, 139 (1949). I
(236) Stamm, R. F., Halverson, F., and Whalen, J. J., Zbid., 17, 104 (1949). (237) Starr, C. E., Jr., and Lane, T., ANAL.CHEM.,21, 572 (1949). (238) Stewart, H. B., and Nielsen, H. H., Phys. Rev., 75, 640 (1949). Sun. C. E.. Parr. R. G.. and Crawford, B. L.. Jr.. J . Chem. Phys., 17, 840 (1949). Sutherland, G. B. B. M., and Lee, E., Repts. on Progresa i n Physics 11, 144 (1948). Szasz, G. J., and Sheppard, N., J . Chem. Phys., 17 93 (1949). Sewarc, M., Ibid., 17, 431 (1949). Taylor, W. J., Ibid., 16, 1169 (1948). Thompson, H. W., and Temple, R. B., J . Chem. SOC., 1948, 1422. Torkington, P., J . C h a . Phya., 17, 357 (1949). 1
Ibid., p. 1026.
Torkington, P., Nature, 162, 370 (1948). Ibid., 163, 96 (1949). Ibid.,p. 446. Ibid.,164, 113 (1949). Torkington, P., Trans. Faraday SOC.,45,445 (1949). Trenner, N. R., Walker, R. W., Arison, B., and Buhs, R. P., ANAL.CHEM.,21, 285 (1949). Treumann, W. B., and Wall, F. T., Ibid., 21, 1161 (1949). Tyler, J. E., J . Optical SOC.Am., 39, 264 (1949). Vago, E. E., Tanner, E. M., and Bryant, K. C., J . Inst .Petroleum, 35, 293 (1949). Voge, H. H., J . Chem. Phys., 16, 984 (1948). Wagner, E. L., and Hornig, D. F., Ibid., 17, 105 (1949). Walsh, A., and Willis, J. B., Ibid., 17, 838 (1949). Walsh, A. D., Trans. Faraday SOC.,45, 179 (1949). Warhurst, E., Ibid.,45, 461 (1949). Webb, A. N., Neu, J. T., and Pitser, K. S., J . Chem. Phya., 17, 1007 (1949). Wells, A. F., J . Chem. SOC.,1949, 55. Welsh, H. L., Crawford, M. F., and Locke, J. L., Phys. Reo., 76, 580 (1949). Westrum, E. F., Jr., and Pitzer, K. S., J . Am. Chem. SOC., 71, 1940 (1949). Whiffen, D. H., and Thompson, H. W., J . Chem. SOC.,1948,1420. White, J. U., Liston, M. D., and Simard, R. G., ANAL.CHEM., 21, 1157 (1949). Winston, H., and Halford, R. S.,J . Chem. Phys., 17, 607 (1949). Wollman, S. H., Rea. Sci. Instruments, 20, 220 (1949). Woods, G. F., and Schwartzmann, L. H., J . Am. Chem. Soc., 71, 1396 (1949). Woltz, P. J. H., and Jones, E. A , , J . Chem. Phys., 17, 602 (1949). Wotiz, J. H., and Miller, F. A., J . Am. Chem. Soc., 71, 3441 (1949). Zerwekh, C. E., Jr., Rea. Sci. Instruments, 20, 371 (1949). Ziomek, J. S., and Cleveland, F. F., J . Chem. Phys., 17, 678 (1949). Ziomek, J. S., Cleveland, F. F., and Meister, A. G., Zbid., 17, 669 (1949). RECEIVEDDecember 21, 1949
RAMAN SPECTRA W. G. BRAUN AND M. R. FENSKE, The Pennsylvania State College, State College, P a .
T
APPARATUS
able for operation by laboratory technicians and makes available t o industry Raman equipment designed primarily for analytical work. The use of electron multiplier tubes in Raman spectroscopy has been reviexed (46)and a brief description of a photoelectric spectrograph used industrially has appeared (39). Kirby-Smith and Jones ( 4 6 ) have described a method of p r e paring optically clear fluorothene scattering tubes of superior chemical resistance for handling fluorine compounds.
.1principal instrumental development of the year has been the introduction of a Raman spectrograph by the Lane-Wells Company. This integrated equipment (Figure 1) consists of a stabilized source and a pen recording spectrometer that can also be used as a photographic spectrograph. The packaged unit, furnished complete with all essential accessories, is said to be suit-
I n general, analytical Raman spectroscopy discussed in the lib erature during the past year has been done using the established procedures outlined briefly in last year’s review (7). Heigl et al. (39) have developed an interesting method for the
HE literature of the past year on analytical Raman spectroscopy has been principally devoted to the extension of the method in relatively narrow fields. Few changes in technique or improvements in instrumentation have been reported. Brief reviews of the subject have been given by Robert (83)and Bareel6 ( 8 ) . A chapter in the book by Harrison et al. (38) offers a good discussion of the methods used.
ANALYTICAL PROCEDURES
12 ,determination of tots1 olefins and total aromatics in hydrocarbon mixtures. Usual analyses for individual compounds are made by determining the intensity (peak height) of selected lines. However, in the analysis of complex hydrocarbon mixtures for total aromatic or total olefin content, the Raman peaks characteristic of the olefinic and aromatic double bond are the result of a large number of individual compounds and because these lines vary slightly in position among the various compounds, a broad band is recorded a t the position characteristic of each of these bond types. These authors established that the area under a recorded peak can be employed as a measurement of the scattering power, and that this is proportional t o the concentration of the characteristic compound type. Using these scattering areas the minimum detectable aromatic content was found t o be approximately 5 volume % a n d the minimum detectable olefin content corresponded to the unsaturation present in a sample containing 5 volume yo hexenes. This method should prove of great value to petroleum chemists because i t provides results that may be obtained rapidly and generally independently of the other constituents of the sample. It could possibly be extended to the estimation of other groups which have characteristic Raman lines such as the C=O, C-Br, C-CI, CEC, and C 4 i groups. Tunnicliff et al. (95)have described an algebraic method for the correction of interfering absorption in spectrophotometric analyses, which may be of value in correcting Raman spectra for the effects of fluorescence or the scattering of interfering substances. The method is based a n the assumption that the interference can be represented as a n analytical function (power series or sum of descending exponentialw) of wave lengths. Ideally the Raman spectrum of a mixture should be a superposition of the spectra of the pure components, the intensities of the bands being proportional to the concentrations of the substances to which they belong. Fortunately, for mixtures of nonpolar or slightly polar compounds, this is true. The u s u d assumption that there is a superposition of spectra is satisfactory when applied to the range of previous experience; i t is, however, only a guide for guessing the performance of mixtures of dissimilar substances. Several papers bearing on the frequency or intensity changes with concentration have appeared this year. The action of vario m solvents on the frequencies and particularly on the relative intensities of several tetrahedral molecules (crtrbon tetrachloride, silicon tetrachloride, and ehloraform) was investigated by Fedosow (8t). The intensities of the lines corresponding t o the oscillations perpendiculrtr to the connecting line between the central atom and the corner atom are subject to changes of as much as -20%. These changes are not correlatable with the magnitude of the dielectric constant or the dipole moment of the solvent. The spectra of ten mixtures of phosphorus trichloride and phosphorus tribromide were obtained by Theimer (Q2), who observed oertain frequency shifts. Bishui and Sanyal ( 8 ) pointed out the change in the intensity ratio of two lines of ethylene bromide in dilute solutions in methanol, benzene, toluene, and hexane. Mixtures of dioxane and beneene represent another of the more unfavorable cases for qusntitative Raman analysis, and Hanle and Heidenreich reported large deviations in the additivity of the spectra. Richards and NieLsen (82) carefully reexamined this system, correcting far the overlapping of the benzene and dioxane bands, and found that the earlier results were erroneous and that the spectra are additive. Goubeau ($2)has pointed out an empirical relationship developed by Otting which can be used for Figure 1.
ANALYTICAL CHEMISTRY correcting the nonadditivity of spectra. Such corrections, however, are not generally useful and whenever an analytical problem is of more than semiquantitative interest the effects of frequency shift and nonlinearity of the intensity-concentration relationship should be investigated. APPLICATIONS
The variety of applications of analytical R a m m spectroscopy continues to he as large BS given in last year’s review. Wihh the exception of the work of Heigl et al. (5Q),all the analyses were performed using procedures previously described. Luther and Lell (60, 61) have devised a semiquantitative scheme whereby type compounds such as olefins, aromatics, dkylcyclopentanes, alkylcyelohexanes, and all\-ylnaphthalenescan be estimated in light colored lubricating oil fractions. Using these data and Waterman analysis data on the colored portions, more useful information on the composition of petroleum fractions is said t o be obtained than by any other analytical method. However, the method for the determination of o l e h s and ammaties previously cited (59) is probahly more accurate for these two types alone. Several additional papers have appeared on the analysis of petroleum fractions (2,4, fig, 8.3, 94). A few other applications of interest include the study of the reaction products of the aluminum chloride treatment of 1-dodecene (65), the cyclization products from the treatment of paraffin hythe products of the condrocarbons with platinized carbon (44), tact reaction of cyclohexene and cyclohexadienes with beryllium orideat400’C.(1,101),andthereductianproductof anacetoneethyl caprylate mixture (99). Addition complexes studied are those of phenol and acetone (58, QO), water and nitric acid, and water and sulfuric acid (IO), various amines and ketones (91), and urotropine and acetic acid (8). The pyrolysis products of various rosin oils (97) were studied. The compound c-fenchene WBS identified by Raman spectra (42), protein hydrolyzrttes were analyzed (81), and the extent of deuterium substitution in deuteriomethyl halides (5) was determined. COLLECTIONS OF SPECTRA
The variety of problems to which any spectral method of analysis can be applied depends to some extent on the siac of the “li-
Recording Raman Spectrograph of Lane-Wells C o m p a n y
V O L U M E 22, NO, 1, J A N U A R Y 1 9 5 0 brary” of spectra of pure materials available to the analyst. A search of Chemical Abstracls will provide the spectra of a great many compounds; however, most of these data are of little use for analytical work because experimental conditions are not given, intensities of lines are not indicated, or relatively impure materials were used. American Petroleum Institute Project 44 a t the National Bureau of Standards is issuing a catalog of Raman spectra t o remedy the paucity of good data. The collection now includes 157 spectra (November 1,1949). Contributions from laboratories which have obtained such data are welcomed, provided the materials examined are relatively pure and the data accurate. The spectra of 40 terpenes ( 9 )and a number of alkyl substituted benzenes (25)have also appeared in the literature. STRUCTURAL STUDIES
A great many papers on the correlation of molecular structure and spectra and on the vibrational analysis of molecules have appeared. Some general review articles are by Goubeau ( J f ) , who reviewed the progress of the work in Germany during 1939 t o 1946, Thompson ( 9 J ) ,and Lecomte (67). Sheppard (85) analyzed the Raman spectral data of a large number of saturated aliphatic hydrocarbons and suggested assignments for the various vibrational frequencies of the CHZgroups. SushchinskiI (88)examined the intensities of several spectral lines of these same compounds and reported a n increase in intensity as the CH, groups increase for the 2853 and 2908 em.-’ lines, while Shorygin (86)studied the intensities of the C=C and CN groups in various molecules. Considerable work has been done on the correlation of molecular structure and spectra, but a great deal still remains t o be done before the Raman method can be used as a qualitative and quantitative procedure for type compounds. Other problems in the vibrational analysis of hydrocarbons which have received attention are: the configuration of cyclohexane (8O), and the force constants of substituted methylacetylenes (68), l,2-butadiene (89), spirohydrocarbons (3, l b ) , and olefins
(4). Additional investigations of interest include: ketene (%), methyl fluorides (SO), hcxafluoroethane ( 7 2 ) , lJ4-dioxane (79), acetonitrile (%), deuterated ethyl bromides (40,56),terpene oxides ( 5 9 ) ,aldehydic and ketonic alcohols (IOO),carbonyls (11,48), dichlorohexafluorocyclobutane (a1 ), phosphoryl and thiophosphoryl halides (18, 19), sulfoxylic and thiosulfurous acid derivatives ( b 9 ) ,metal dialkyls (M), tetrahalides (41,98),pentahalides (70), polychloro compounds ( 2 7 ) , halogenated ethylenic compounds ( 4 7 ) ,and the use of deuterium in the study of vibrational frequencies (54). Various papers have appeared on the approximate computation of vibration frequencies of alcohols, ethers, and amines (32, 84), hydrocarbons (SO), and other miscellaneous compounds (244). CRYSTAL STRUCTURE
rl great deal of a o r k has been done on the study of the Raman spectra of crystals, entirely devoted to crystal structure analysis rather than to chemical analytical problems. The theory, which is a t present in a somewhat unsettled state, has been reviewed (14, 15,43, 66,67,73)and detailed studies of the spectra of a great many crystals have been made. These include: diamond (60,74, 87), sodium chloride (33, 51, 69, 7 S ) ,magnesium oxide ( 7 6 ) ,alumina (5S), topaz (54), calcite ( I S , 28), ammonium chloride (16, 49, 62), ammonium bromide (55), potassium bromide (JJ), lithium and sodium fluorides (77), oxalates (6J), sylvite ( 7 8 ) ,alkali sulfates ( 1 7 ) ,benzene ( 2 6 ) ,and the diphenylbenzenes (71). The spectra of water of crystallization ( 6 4 )and the differences in the spectra of crystals a t various temperatures have also been examined (49, 52, 65, 96). Harrand ( 3 7 ) has described a new arrangement for obtaining the spectra of crystals.
13 LITERATURE CITED
Arbumov, Yu. A., Batuev, M. I., and Xelinskii, N. D., Bull. acad. sci. U.R.S.S., Classe sci. chim., 1945, 665. Barcel6, J., Inform. quim. anal. ( M a d r i d ) , 1, 182 (1947). Batuev, M. I . , ’ B u l l . mad. sci. U.R.S.S., Classe sci. chim., 1947, 3.
Bazhulin, P. A . , and Sterin, Kh. E., Ibid., Sir. phys., 11, 466 (1947).
Beersmans, J., and Jungers, J. C., Bull.
SOC.
chim. Bebes,
56, 238 (1947).
Bishui, B. LM., and Sanyal, S. B., I n d i a n J . Phys., 21, 233 (1947).
Braun, W. G., and Fenske, Id.R., ANAL.CHEW., 21, 12 (1949). Carroll, K. K., and Wright, R. H., Can. J . Research, 25B, 481 (1947).
Castillo, E. B., Trabajos lab. bwquim.
y qudm. aplicada, Inst. “Alonso Barba,” Univ. Zaragoza, Facultad cienc., 86,. 11. 2/3, 255 (1941). ChQdin,J., and FQnQant,S.,J . chim. phys., 45, 66 (1948). Cherrier, C., Compt. rend., 225, 930 (1947).
Cleveland, F. F., Murray, M. J., and Gallaway, W. S.,9. Chem. Phys., 15, 742 (1947).
Couture, L., Ann. phys., 2, 5 (1947). Couture, L., Contrib. Btude structure mol., Vol. comme‘m. Victor Henri, 1947148, 105.
Couture, L., J . phys. radium, 9, 84 (3) (1948). Couture, L., and Mathieu, J. P., Compt. rend., 226, 1261 (1948).
Couture, L., and Riche, N., J . phys. radium, 10, 151 (1949). Delwaulle, M . L., and Frangois, F., Compt. rend., 225, 1308 (1947). Ibid., 226,894 (1947).
Delwaulle, M. L., and Francois, F., Contrib. e‘tude structure mol., v o l e comme’m. Victor Henri, 1947148, 119.
Edgell, W. F., and Kite, F. E., J. Chem. Phys., 15,882 (1947). Fedosow, J., SOC.Sci. Fennica Commentationes Phys.-Math., 14. 1 (1948).
FehQr, F:, Kolb, W., and Leverena, L., Z . Naturforsch., 2a, 454 (1947).
Finkel’shtein, A. I., J. Phys. Chem. (U.S.S.R.), 21, 1243 (1947).
Fromherz, H., Buren, H., and Thaler, L., Angew. Chem., A59, 142 (1947).
Fruhling, A., J.phys. radium, 9, 88 (1948). Gerding, H., and Rijnders, G. W. A . , Rec. trav. chim., 66, 225 (1947).
Giulotto, L., and Olivelli, G., J . Chem. Phys., 16, 555 (1948). Goehring, M . , Chem. Ber., 80, 219 (1947). Gopshtein, N. M., J . Phys. Chem. (U.S.S.R.), 22, 3 (1948). Zhid..
D. 11.
Goubeau, J., F I A T Rev. German Sci., 1939-46; Phys. Chem., 1948, 25-36. Gross, E. F., and Stekhanov, A. I., Bull. acad. sci. U.R.S.S., SBT.phys., 11, 364 (1947). Halverson, F., Revs. Modern Phys., 19, 87 (1947). Halverson, F., Stamm, R. F., and Whalen, J. J., J . C’hem. Phys., 16, 808 (1948). Harp, W. R., Jr., and Rasmussen, R. S., Ibid., 15, 778 (1947). Harrand, M . , J . phys. radium, 9, 81 (1948). Harrison, G. R., Lord, R. C., and Loofbourow, J. R., “Practical Spectroscopy,” New York, Prentice-Hall, 1948. Heigl, J. J., Black, J. F., and Dudenbostel, B. F., ANAL. CHEX..21.554 (1949). Hemptinne, M. de, Contrib. e‘tude structure mol., Vol. comme’m. victor Henri, 1947148, 151. Hildebrand, J. H., J . Chem. Phys., 15, 727 (1947). Htlckel, W., and Kindler, H., Chem. Ber., 80,197 (1947). Kastler, A., Contrih. Btude structure mol., Vol. wmmim. Victor Henri, 1947 148, 93. KazanskiI, B. A., Liberman, .4.L., and Batuev, M ,I., Doklady Akad. N a u k U.S.S.R., 61,67 (1948). Kinell, P. O., and Traynard, P., Acta Chem. Scand., 2, 193 (1948). Kirby-Smith, J. S., and Jones, E. .4.,J . Optical SOC.Am.. 39, 780 (1949). Kirrmann, A , Bull. S O C . chim. France, 1948, 163. Kohlrausch, K. W. F., Acta Phys. Austriaca, 1, 113 (1947). Krishnan, R.S.,S u t u r e , 160, 711 (1947). Krishnan, R. S., PTOC. I n d i a n Acad. Sci., 26A, 399 (1947). Ibid., p. 419. Ibid., p. 432. Ibid.. u. 450. (54) Ibid..D. 460 (55) Ibad , i7A, 321 (1948). (56) Langseth A , and Bak, B.. Kgl. Danske Videnskab. Selskub, Mat fys. Medd., 24, No. 3, 16 pp. (1947).
A N A L Y T I e A L CHEMISTRY Lecomte, J., Contrib. &de atructure mal., Vol. wmmdm. Victor Henri, 1947 148, 133. Lecomte, J., Gray, E., and Taboury, F. J.. Bull. soc. chim. France, 1947, 774. Lombard, R., Ibid., 1947,522. Luther, H., Er&Z u . Kohle, 2,179 (1949). Luther, H., and Lell, E., Angew. Chem., 61A,63 (1949). Maniere, B., and Barohewitz, P., Groupemat franc. devel. recherche8 C U ? T O ~ U ~ ~Note ., Tech. 56, (1946). Marignan, R., Bull. soc. chim. France, 1948,350. Zbid., p. 351. Masuno, M., Asahara, T., and Ishiguro, T., J. SOC.Chem. I n d . J a p a n , 49,192 (1946). Mathieu, J. P., J . phys. radium, 9,83(1948). Matossi, F.,and Mayer, R., Phya. Rm.,74,449(1948). Meister, A. G., J.Chem.Phye., 16,950 (1948). Menzies, A.C., and Skinner, J., J . phys. radium, 9,93 (1948). Moureu, H.,Sue, P., and Magat, M., Contrib. Pude structure mol., Vol. commhm. Victor Henri, 1947148,125. Mukerji, S. K., and Singh, L., Phil. Mag., 37,874 (1946). Pace, E.L., and Aston, J. G., J . Am. Chem. SOC.,70,566 (1948). Raman, C.V., Proc. Indian A d . Sci., 26A,339 (1947). Zbid., p. 356. Ibid., p. 370. Ibid., p. 383. Ibid., p. 391. Ibid., p. 396. Ramsay, D.A., Proc. Roy. Iyoc. (London),A190, 662 (1947). Ramsav. D. A,. and Sutherland. G. B. B. M.. Ibid.. A190. 245 ‘ (1947). ’ Renard, M., M e n . 8oc. my. aci. LUoe. 7,No. 1 (1945).
(82) Richards, C. M., and Nielsen, J. R., ANAL. CHEM.,21, 1036 (1949). (83) Robert, L.,Rev. inst. franG. pdtrole et A n n . combustibles liquidee. 3, 245 (1948). (84) Ryskina, S. I., J . Phys. Chem. (U.S.S.R.), 22,21 (1948). (85) Shemard, N.,J . Chem. Phus., 16,690 (1948). (86) Shorygin, P. P., J . Phys. Chem. (U.S.S.R.), 21,1125 (1947). (87) Smith, H. hI. J., Phil. Trans. Roy. SOC. (London), A241, 105 (1948). (88) Sushchinskii, M. M.,Bull. acad. sei. U.R.S.S., Skr. phya., 11, 341 (1947). (89) Szasz, G . J., McCartney, J. S., and Rank, D. H., J. Am. Chem. SOC.,69,3150 (1947). (90) Taboury, F. J., and Queuille, J., Bull. SOC. chim. France. 1947, 772. (91) Taboury, F. J., Thomassin, R., and Perrotin, Mlle., Ibid.. 1947, 783. (92) Theimer, O., Acta Phys. Austriaca, 1, 188 (1947). (93) Thompson, H.W., J . phys. radium, 9,172 (1948). (94) Treshchova, E. G., and Tatevskii, V. M., Doklady Akad. Nauk U.S.S.R., 61,841 (1948). (95) Tunnicliff, D. D., Rasmussen, R. S., and Morse, M. L., ANAL. CHEM., 21,895(1949). (96) Vassas-Dubuisson, C., J . phys. radium, 9,91 (1948). (97) Vassiliev, G.A.,Bull. SOC. chim. France, 1947,657. (98) Welsh, H.L., Crawford, M. F.,and Scott, G. D., J. Chem. Phys., 16, 97 (1948). (99) Wiemann, J., Bull. SOC. chim. France, 1947,479. (100) Wiemann, J., and Maitte, P., Ibid., 1947,764. (101) Zelinskii, N. D., Arbuzov, Yu. A., and Batuev, iM.I., Bull. acad. sci. U.R.S.S., Classe sei. chim., 1945,486. RECEIVED Uovrmber 14, 1919.
ULTRAVIOLET ABSORPTION SPECTROPHOTOMETRY E. J. ROSENBAUM, Sun Oil Company, Norwood, Pa.
D
URING 1949 few really new developments in the field of ultraviolet absorption spectrophotometry have come to the attention of this reviewer. There has been some progress, but this has been mostly in the direction of the refinement of existing methods and their extension to additional analytical problems. The absorption spectra of a number of compounds have been reported, usually in connection with molecular structure investigations. Of course, each spectrum is potentially the basis of a new analytical application. A rather detailed description of a method for determining individual Ce, C,, and C8 aromatic hydrocarbons in mixtures containing up to six of these components is given by Tunnicliff, Brattain, and Zumwalt (19). These authors include in their paper a considerable amount of useful basic information on calibration, test for and removal of interfering absorbers, etc. Vaughn and Stearn ($1) carry out the analysis of an isomeric rylene mixture in an unconventional way by making absorption measurements a t four wave lengths, calculating two pairs of differences between these measurements, and using these differences with a “working chart” set up during calibration to arrive at the desired analysis. The working chart is a ternary composition diagram based on absorption measurements on a series of mixtures of known composition made up from pure xylene samples. This method eliminates errors due t o background absorption which is independent of wave length and it is not limited in accuracy by deviations from Beer’s law because the calibration is based on mixture data. The analysis of mixtures of xylene isomers is also treated by Shostenko and Shtandel (15). The spectra of the four butylbenzenes and the three diethylbenxenes are reported by Stair (IC), who also discusses the analytical usefulness of the various absorption bands. The determination of total aromatics in gasoline is carried out h y Yzu and Doblas (W), using absorption in the range 260 t o 270 mp.
The problem of correcting for interfering absorption when it is impractical to remove all of the interfering material is treated by Tunnicliff, Rasmussen, and Xorse (20). By making use of spectrophotometric measurements a t a sufficient number of spectral positions, they algebraically obtain and correct for the interfering absorption. This method is reported t o give good results when applied t o the analysis of monocyclic aromatic hydrocarbons and of naphthalene in samples showing strong interference. The determination of naphthalene and the methylnaphthalene^ has received further attention. . 4 method is described by Armstrong, Grove, Hammick, and Thompson (1) who use a Hilger spectrograph and photographic photometry t o obtain their analytical data. A similar photographic method is applied by Bryant, Kennedy, and Tanner (S) t o the determination of naphthalene and its methyl derivatives in Trinidad petroleum Coggeshall and Glessner ( 4 ) describe a method of employing the Beckman spectrophotometer which they apply to hydrocarbon mixtures boiling in the kerosene range. An average error of 0.2% based on the total sample is reported for analyses of knonn mixtures. These authors present a simple empirical method for making a background correction in the determination of naphthalene A somewhat unusual application of ultraviolet spectrophotometry is the determination of biphenyl in orange peel hy S t e p and Rosselet (17‘). Murray ( 1 3 )determines total phenols in gasolines by extracting them with aqueous alkali and measuring ahsorption at 290 mg. LeRosen and Wiley (10) extract pyridine and related compounds from hydrocarbon mixtures by means of dilute phosphoric acid and determine their concentration by measurements at 255 mg. Benzaldehyde, present up to concentration of 0.1% as a contaminant in benzyl alcohol, is determined by Rees and Anderson ( 1 4 ) n h o dissolve the sample in a watermethanol mixture and measure absorption a t 283 mp. A method for determining acetaldehyde in monovinyl acetate a t concentra-
