12
ANALYTICAL CHEMISTRY
(287) (288) (289) (290)
Shurcliff,W. A . , J . OpticaE SOC.Am., 39, 1048 (1949). Sinha, S. P., J . Chem. Phys., 18, 217 (1950). Sippel, A., Z. Naturforsch., 40, 179 (1949). Smith, A. L., Keller, R. E., and Johnston, H. L., Phys. Rev.,79, 728 (1950). (291) Smith, D. C.,Nielsen, J . R., and Claamen, H. H., J . Chem. Phys., 18,326 (1950). (292) Smith, D. C., Pan, C. Y., and Nielsen, J. R., Ihid., 18, 706 (1950). Smith, F. .4., and Creits, E. C., ANAL.CHEM.,21, 1474 (1949). Sobotka, H., and Stynler, F. E., J . Am. Chem. SOC.,72, 5139 (1950). Stafford, H . W.,Francel, R. J., and Shay, J. F., ANAL.CHEM., 21,'1454 (1949). Stroupe, J. D., Ihid., 22, 1125 (1950). Pwern, D., Knight, H. B., Shreve, 0. D., and Heether, M. R., J . Am. O i l Chemists' SOC.,27, 17 (1950). Szasa, G. J., J . Chem. Phys., 18, 393 (1950). Ihid., p. 1417. Sawarc, &I., and Evans, M.G., Ibid., 18, 618 (1950). Takeuchi, Tsuguo, Kagaku n o Ryoiki ( J . J a p a n . Chem.), 4, 490 (1950). Talley, R. M., Kaylor, H. M., and Nielsen, A. H., Phya. Ret.., 77, 529 (1950). Tanaka, Yoshio, Proc. Phys. SOC.J a p a n , 5, 64 (1950). Taylor. R. C., J . Chem. Phys., 18, 898 (1950). Taylor, W.J., Ibid., 18, 1301 (1950). Tetlow, K. S., Research (London), 3, 187 (1950). Thomas, O., J. Chent. Phys., 18, 761 (1950). Thompson, H. W., and Miller, C. H., Trans. Faraday SOC.,46, 22 (1950). Thompson, H. TV.,Vago, E., Corfield, M.,and Orr, S., J . Chem. SOC.,1950, 214. Thornton, V., and Condon, F. E., ANAL.CHEM.,22,690 (1950). (311) Tilton, L. W., Plyler, E. K., and Stephens, R. E., J. Optical SOC.Am., 40, 540 (1950). (312) Tilton, L. W.,Plyler, E. K., and Stephens, R. E., J . Reseurch Natl. Bur. Standards, 43, 81 (1949). (313) Torkington, P., J . Chem. Phys., 17, 1026 (1949). (314) Ibid., p. 1279. (315) Ibid., 18, 93 (1950). (316) Ibid., p. 407. (317) Ibid., p. 768. (318) Ibid., p., 773. (319) Ibid., p. 1373. (320) Torkington, P., J . OpticaE SOC.Am., 40, 481 (1950). (321) Torkington, P., Trans. Faraday Soc., 46, 27 (1950). (322) Trenner, N. R., A N . ~ LCHEM., . 22, 405 (1950).
(323) Turkevich. J., McKenzie, H. A . , Friedman, L., and Spurr, R., J . Am. Chem., 71,4045 (1949). (324) Turnbull, J. H., Whiffen, D. H., and Wilson, R., Chemistry & Industry, 33, 626 (1950). (325) Van Asselt, R., and Williams, D., Phys. Rw.,79, 1016 (1950). (326) Van Vleck, J. H., and hlargenau, H., I b X , 76, 1211 (1949). (327) Vincent, J., J. phya. radium, 11, 1 (1950). (328) JVagner, E. L.. and Hornig, D. F., J . Chem. Phys., 18, 296 (1950). (329) Ibid., p. 305. (330) Waldron, R. D., and Badger, Ii. RI., Ibid., 18, 566 (1950). (331) Walsh, A., Roy. Azisfralian Chem. Inst. J . and Proc., 16, 371 (1949). (332) Ralsh, A . , and Willis, J. B., J . Chem. Phys., 18, 552 (1950). (333) Washburn, W. H., and Krueger, E. 0.. J . Am. Pharm. Assoc., Sci. Ed., 38, 623 (1949). (334) Washburn, W.H., and Krueger, E. O., J . Am. Phum. Assoc., 39,473 (1950). (335) Weiss, K., Ann. Physik (6), 2, 1 (1948). (336) White, J. U., ANAL.CHEM.,22, 768 (1950). (337) White, J. G., Rev. Sci. Instruments, 21, 629 (1950). (338) White, J. t-.,and Liston, hi. D., J . Optieal SOC.Am., 40, 93 (1950). (339) Ibid., p. 29. (340) Wiberley, S. E., and Bassett, L. G., ANAL. CHEY., 22, 841 (1950). (341) Willmott, J. C., Xature, 162, 996 (1948). (342) Willmott, J. C., Proc. Phys. SOC.(London), A63, 389 (1950). (343) Wilson, M. K., and Badger, R. M.,J . Chem. Phys., 17, 1232 (1949). (344) Wilson, hl. K., and Ogg, R. A , , Ibid., 18, 766 (1950). (345) Rise, J. H., and Elmer, J. T., Ihid., 18, 1411 (1950). (346) Tolfhard, H. G., and Parker, R. G., Proc. Phys. SOC.(London), A62,722 (1949). (347) Wood, D. L., Rev.Sci. Instruments, 21, 764 (1950). (348) Woodward, L. A., Nature, 165, 198 (1950). (349) Wotis, J. H., Miller, F. A . , and Palchak, R. J., J . Am. Chem. SOC.,72,5055 (1950). (350) Y-amamoto, Gi-ichi, and Onishi, Gaishi, Sci. Re&. (T8hoku Univ.), 1,5 (1949). (351) Ibid., p. 71. (352) Yaroslavskii, N. G., Zhur. Fiz. Khim.,24, 68 (1950). (353) Zbinden, R., Baldinger, E., and Ganr, E., Helv. Phys. Acta, 22, 411 (1949). (354) Zhurkov, S. N., and Lenn, B. Y., Doklady A M . N a u k S.S.S.R. 72,269 (1950). RECEIVED December 18, 1950.
UItraviolet Absorption Spectrophotometry E. J. ROSENBAUM, Sun OiI Co., Norwood, Pa.
F
ROM a survey of the literature on ultraviolet absorption spec-
trophotometry published during the past year, several trends can be identified. There s e e m to be a growing interest in the determination of inorganic compounds by this method. An increasing number of spectra have been obtained %-ith the Cary recording spectrophotometer which, u p to the present,, has had only a very brief description in the literature (Sf). The rate a t which spectra are being published continues to be high, but only a minor fraction of these spectra are applied to analytical problems, the major interest being usually in a correlation of spectra with molecular structure. Little has appeared on instrumental or apparatus development. Papera by Kinsey (22) and by Shugar (So') deal with the problem of using the Beckman quartz spectrophotometer for the analysis of very small samples. Microcuvettes and methods for positioning them are described. A review on microsp ec-
troscopy by Loofbourow (23) includes a description of methods of obtaining ultraviolet absorption spectra of minute samples. Bastisn, Weberling, and Palilla (1) discuss the use in spectrophotometric analysis of a reference solution which contains the absorbing component of interest. They illustrate the advantagee of this differential method, but point out that i t requires wider slits than would otherwise be necessary and that in some case8 the resulting loss of resolving power and increase in stray radiation might be a handicap. An interesting variation of the usual procedure for multicomponent quantitative analysis is presented by Perry, Sutherland, and Hadden (52). I n setting u p their calibration they use measurements on solutions of the individual components whose concentrations are not known, the only requirement being that the absorbances (optical densities) fall within the optimum range of 0.4 to 1.0. I n addition, measurements on one mixture of known composition must be used. The
V O L U M E 2 3 , NO. 1, J A N U A R Y 1 9 5 1 authors call attention to the facts that the method is not applicable to samples which contain nonabsorbing components and that validity of Beer’s law is assumed. Analyses of the following systems are given as examples: xylenes, with and without ethylbenzene, diethylbenzene and sec-butylbenzene, and benzene and toluene. On a more theoretical level, the errors introduced into spectrophotometry by the effect of finite slit width are treated in some detail by Hardy and Young (19) and bv Eberhardt (11). BIOLOGICAL APPLICATIONS
The application of ultraviolet absorption spectrophotometry
to syst,ems of biological importance continues to be a useful tool. Racker (53) studies the enzymic formation of fumaric and cisaconitic acids by means of spectrophotometric measurements. The estimation of vitamin A in the presence of interfering materials is treated by McGillivray (g6). Vacher and Faucquembergue (.75) make usc of the shift of the absorption spectra with change in pH to identify and determine ascorbic acid and pyridoxime. The spectra of sulfuric acid chromogens of the adrenal steroids and related compounds have been studied by Zaffaroni (43),who calls attention to the value of these spectra for analysis. Holzmari and Niemann (21) find that measurement of the absorption a t 260 mp is a sensitive method for following the purification of a blood group A substance. The more active fractions have weaker absorption. The determination of nicotine is treated in d e b i l by Willits and co-workers (42). Vacher and Tounichon (39) identify and determine nicotine and related compounds by treating a sample with dilute cyanogen bromide solution and measuring the absorption of the resulting derivatives in the range 350 to 400 mp. Grant and Jones (18) determine the alkaloids i n cinchona bark by using absorption a t 316 mp for the quinine alkaloids and a t 348 mp for the cinchonine alkaloids, thus treating niistures as two-component systems. Bennett and Niemann (3) use ultraviolet spectra to show that they found a transacylation reaction in the Erlenmeyer-Plochl synthesis of some amino adds. Benzylpenicillin is determined by Garlock and Grove (16), who separate this conipound by solvent extraction and measure absorption a t 264.5 mp. Trenner (57) in a paper on physicalchemical measurements on the penicillins discusses some analytical applications of ultraviolet spectrophotometry. Schauenstein and Treiber (34) study the spectrum of actomyosin and conclude that they can determine tryosine and tryptophan quant’itatively. Loofbourow, Gould, and Sizer (94) show that absorption is useful as an index of purit,y of collagen from various sources.
13 ultraviolet absorption spectra of the 8-hydroxyquinoline derivatives of gallium and thallium, and (SO)describe the spectra of the 8-quinolinol chelates of aluminum, gallium, indium, and thallium. ORGANIC ANALYSIS
I n a review of the determination of organic functioiiality by molecular spectroscopy, Coggeshall ( 7 ) includes applications of ultraviolet absorption spectroscopy for this purpose. Davidow and Woodard (9) determine benzene hexachloride by converting it to 1,2,4trichlorobenzene and measuring absorption a t 286 mp. They find a base-line technique useful for minimizing interferences. Warshowsky and Schantz (41) detcrmine 2,4dichlorophenoxyacetic acid in soil by applying the countercurrent distribution method to separate the desired compound and then measuring absorption a t 284 mp to determine it. Another good example of the use of countercurrent distribution followed by spectrophotometric determination is given by Goluinbic ( I T ) , who descrihrs the analysis of technical grade phenanthrene cont,aining anthracene and carbazole, and of a mixture of carbazole homologs. IIazlett, Hannan, and Wells (20) apply spectrophotometric techniques to th(a detcrniiiiation of anthracene in rrude anthracene cake. Chevallier and Burg ( 5 ) determine polyethylenic esters of acids containing two, three, or four double bonds, by measuring absorption nt 234, 268, and 310 nip, respectively. Evstigneev and Nikiforova (12) find that absorption a t 280 and 230 mfi can be used to determine hydroxvmethylfurfural and humus substances in heated sugar solutions. Fuchs (15) dietills pentosea and uronic acids with hydrochloric or hydrobromic acid and determines furfural in the distillat,e from the absorption at 277 mp. Berton (4) detects small concentrations (- 0.1 mg. per liter) of per- and trichloroethylenes and other chlorinated solvents in the vapor state by examining the wave-length region 225 to 250 mp. Benzene and toluene are determined in “petruleum ether” by Lundgren and Wallen (86) and aromatic hydrocarbons in cracked gasolines are determined by VarshavskiI (40). Dietz, Dole, and Priestley (10) find that the difference in ultraviolet absorption between petroleum wax and the oil associated with it is sufficient to permit the determination of residual oil in the wax. Absorption in the near-ultraviolet can be used to evaluate the quality of engine oils according to Clark, Mueller, and Culmer (6),mho report correlations bet,ween standard petroleum tests and absorption yeasurements. During the past year several books (3, 13, 27) have appeared which contain helpful review of analytical applications of ult,raviolet absorption spectrophotometry. LITERATURE CITED
INORGANIC ANALYSIS
In the field of inorganic analysis several workers have taken advantage of the fact that some ions which have little or no absorption in the visible have strong absorption in the ultraviolet For esample, Telep and Bolts (36) determine molybdenum in the concentration range 0 to 150 p,p,ni. by treating an acidic molybdate solution with hydrogen peroxide and then measuring absorption a t 330 mp. Their paper includes a study of interfering ions. Freedman and Hume (14) use absorption a t 315 mp to determine ceric ion in sulfuric acid solution. They also describe a method of applying radioactive cerium as a tracer to correct for incohplete separation from other ions. In connection with a study of the spectra of aqueous periodate solutions, Crouthamel and co-workers (8) discuss the analytical significance of their results. A wave length of 222.5 mp and a p H of 5.0 are considered as optimum for acidic solutions of periodates. The use of spectrophotometry for the estimation of some of the rare earth ions is reported by hloeller and Brantley (28),who recommend a wave length of 273 mp for gadolinium. hfoeller and Cohen (89) study the analytical applications of the near-
Bastian, R., Weberling, R., and Palilla, F., ANAL.CHEM., 22,160 (1 950). Bennett, E. L.,and Niemann, C., J . -4m.Chem. SOC.,72, 1803 (1960). Berl, W.B.,ed., “Physical hlethods in Chemical hnalysis,” Vol. I, New York, Academic Press, 1950. Berton, A,, Bull. 8oc. chim. France, 1949,858. Chevallier, A., and Burg, C., Ibid., 1949,707. Clark, G.L., hfueller, hf. H., and Culmer, T. W., A N ~ LCHEM., . 21, 1485 (1949). Coggeshall, N. D., Ibid., 22,381 (1950). Crouthamel, C. E., Meek, H. V., Martin, D. S., and Banks, C. V., J . A m . Chem. SOC.,71,3031 (1949). Davidow, B., and Woodard, G., J . Assoc. Ofic. Aer. Chemists, 32, 751 (1949). Dietz, W. 9., Dole, 8. H., and Priestley, R., Proc. A m . Petroleum Inst., 111, 29M, 60 (1949). Eberhardt, W . H., J . Optical SOC.A m . , 40, 172 (1950). Evstigneev, V. B., and Nikiforova, V. N., Biokhimiya, 15, 86 (1950). Farkas, A., ed., “Physical Chemistry of the Hydrocarbons,” Vol. I, New York, Academic Press. 1950. Freedman, A. J., and Hume, D. N., ANAL.CHSM.,22, 932 (1950). Fuchs, L., Monateh., 81,70 (1950).
ANALYTICAL CHEMISTRY
14 (16) Garlock, E. A., Jr., and Grove, D. C., J . Am. Pharm. Assoc., 39, 398 (1950). (17) Golumbic, c., ANAL.CHEM.,22, 579 (1950). (18) Grant, H. S.,and Jones, J. H., Ibid., 22, 679 (1950). (19) Hardy, A. C., and Young, F. hl., J . Optical SOC.Am., 39, 265 (1949). (20) Haslett, F. P., Hannan, R. B., Jr., and Wells, J. H., ..~NAL. CHEM.,22, 1132 (1950). (21) Holaman, G., and Niemann, C., J . Am. Chem. SOC.,72, 2044 (1950). (22) Kinsey, V. E., ANAL.CHEM.,22, 362 (1950). (23) Loofbourow, J. R., J . Optical SOC.,Am., 40, 317 (1950). (24) Loofbourow, J. R., Gould, B. S.,and Siaer, I. W., Arch. Biochem., 22,406 (1949). (25) Lundgren, P., and Wallen. O., Svensk. Farm. Tid., 54, 273 (1950). -4., ANAL. CHEM.,22, 494 (1950). (26) RlcGillivray, (27) RIellon, M. G., ed., “Analytical Absorption Spectroscopy,” S e w York, John Wiley & Sons, 1950. (28) hfoeller, T., and Brantley, J. C., ANAL. CIIEM.,22, 433 (1950). (29) Moeller, T., and Cohen, A. J., Ibid., 22, 686 (1950).
mr.
(30) Afoeller, T., and Cohen, -4.J., J. Am. Chem. SOC.,72, 3546 (1950). (31) Munch, R. H., Ind. Eng. Chem., 39, 75,4 (April 1947). (32) Perry, J. A., Sutherland, R. G., and Hadden, N., ANAL. CHEM., 22, 1122 (1950). (33) Racker, E., Biochem. et Biophys. Acfn,4, 211 (1950). (34) Schauenstein, E., and Treiber, E., J . Polvmer Sei., 5 , 145 (1950). (35) Shugar, D., Bull. soc. chirn. b i d , 31, 1659 (1949). C m x , 22, 1030 (1950). (36) Telep, G., and Boltz, D. F., ANAL. (37) Trenner, K.R., Ibid., 22, 405 (1950). (38) Vacher, hl., and Faucquembergue, D., BUZZ.SOC. chim. biol., 31, 1419 (1949). (39) Vacher, M., and Tounichon, 0,,Ibid., 31, 1430 (1950). (40) S’arshavskiI, Y. hl., Zavodskaya Lab., 15, 1476 (1949). (41) Warshowsky, B., and Schants, E. J., ANAL.CHEM.,22, 460 (1950). (42) Killits, C. O., Swain, M. L., Connelly, J. A,, and Brice, B. A , , Ibid., 22, 430 (1950). (43) Zaffaroni, A., J . Am. Chem. SOC.,72, 3828 (1950). RECEIVED November 10, 1950.
X-RAY ABSORPTION H E K M i N i. LIEBH-IFSKY, General Electric Co., Schenectady, Y. Y .
P
XPERS presented a t scientific meetings since the last review
show that analytical methods based upon x-ray absorption and related phenomena are being put increasingly to use. Among these meetings was a Symposium on Instrumental Methods for the Determination of Tetraethyllead in Gasoline, held by a subdivision of Committee D-2, American Society for Testing Materials. Of the four papers on x-ray methods given on that occasion, only the introductory paper (22) was published 29) have now appeared in time for this review. The others (4,6, CHEMISTRY,and the four will be reviewed as a in ANALYTICAL group later. Other papers as yet unpublished are listed chronologically in Table I. Two of these deal with the determination of uranium, a logical field for methods of the kind considered here. Clark has described the field under review in the excellent first chapter of a recent treatise on physical methods in chemical analysis ( 2 ) . The arrangement and nomenclature oE the previous reviews (20, 81) are retained here, and a discussion of important developments in the analysis of biological materials is included. X-RAY ABSORPTION SPECTROMETRY
the determination of minute amounts of calcium and phosphorus in biological material. His subsequent work, both with monochromatic and with filtered beams, warrants discussion not only because of its great importance in biological problems, but because the analytical chemist may find it profitable to adapt Engstrom’s techniques in special cases. Usually the method of Glocker and Frohnmayer (n-hich might be called differential absorptiometry with monochromatic beams) consists in making absorbance measurements a t several wave lengths above and several below an absorption edge of the element sought. An x-ray spectrometer is consequently required. Engstrom’s “spectrometer” is novel and simple, and appears to give radiant energy that is satisfactory for microanalyses where the utmost precision is not sought. Collimated x-rays sufficiently low in wave length fall upon a sheet of an element mounted (asone of 16) on a disk that can be rotated. The K-lines of this element are excited and passed (after filtering, if desired) through the sample and to the detector, usually a photographic film, though others will do. In this way, intensity measurements are made a t one wave length above, and one below, that corresponding to an absorption edge of the element being determined. The example below (compare with Equations 6 to 10, 20) will serve in lieu of further discussion.
The first review (20) mentioned that Engstrom (13) had successfully applied the method of Glocker and Frohnmayer (18) to
Table I. duthors
Iron has its K-absorption edge a t 1.74 A., and for its determination Engstrom used the K a lines of nickel (1.66 A.) and cobalt (1.79 A.‘). Suppose z is the proportion of iron in a s a m p l e weighing m grams. The fundamental absorption Recent Unpublished Papers on X-Ray Absorption equations are:
Liebhafsky H. A and Winaluw, E . H.. GenLral Electric Co. Hughes, H. K.. and Wilczewski. J. W , Socony-Vacuum Co. Levine, S. W.. Atlantic Refining Co. Lambert, M. C., General Electric co. Lamb, F. W.. and Niebylski, L. >I.E t h y l Corp. Bartlett T. W Union Carbide SCarbdn Corp.”
Title Differential .kbsorbance Rleasurements on Polychromatic X-Ray Beams Rapid X-Ray Determination of Sulfur in Distillate Fuels
Determination of Sulfur in Petroleum Fraction b y X-Ray d b sorption X-Ray Photometric Determination of Uranium Determination of Total Chlorine in Chlorinated Benzenes b y X-Ray Bbsorptiometry X-Ray Photometric Deterruination of Uranium in Solution
Meeting CHEMIClt SOCIETY, 117th Meeting, Houston, Tex., April 13, 1950 Symposium on Analytical Research, American Petroleum Institute, Cleveland, Ohio, May 1, 1950 Spplied Spectroscopy Society meeting, S e w York. May 26-27, 1 _win ”-Ai\fERICAN CHEMICAL SOCIETY, Pacific Northwest Regional Meeting, Richland, Wash., June 9, 1950Gordon Research Conference Colby Junior College New London, N. H., 4ug. 2, i950 -4XERICAS CHEMICAL SOCIETY 118th Meeting, Chicago, 111.:
A\lERICAS
Bept. 7, 1950
and
+
log IL/I’ = kb,mx kgm ( 1 - 2 ) ( A = 1.64 A.) (2) when the k’s are proportionality constants ( 2 0 ) and the subscript S refers to the sample less iron, free or combined.
