Microchemical Applications of Catalytic and Induced Reactions PHILIP W. WEST Coates Cheniicul Laboratories, Loriisiana State I‘nirersity, Baton Rorrpe, La.
This study was undertaken to review the status of catalytic and induced reactions. Many applications of these reactions to qualitative and quantitative analysis have been disclosed and their advantages in regard to sensitivity and selectivity pointed out. Principles involved in the use of these reactions have been surveyed, and a classification of the reaction types is presented. The work is significant because it directs attention to an important phase of analytical chemistry that seems to have been neglected by many investigators.
M
NATURE OF CATALYZED AND INDUCED REQCTIONS
A S Y e u n i p l e s are recorded of uses of catalytic activity in
analytical chemistry (SO, 1Q4),with much of the emphasis being placed on quantitative implications. Because catalytic effects may often be uniquely significant in qualitative analysis, it seems pertinent also to consider their attributes which are of special value in spot test work. I t is significant t h a t one investigator, Feigl, has contributed many of t h e tests involving catalytic activity and It should prove profitable for other investigators to initiate studies esploring the possibilities of such reactions. Probably the earliest work on the use of catalyzed reactions in qualitative analysis to gain general recognition was the so-called “glow test” described by Curtman and Rothberg ( 1 9 ) in 1911, and adapted to spot test work by Hahn (65). This test is applied in the detection of the platinum metals and depends on the abilities of these metals t o adsorb gases, particularly hydrogen. When a drop of a solution containing a platinum metal is evaporated and then ignited strongly on a strip of asbestos paper, a fine deposit of the metal is obtained. When such a spot is introduced into a stream of hydrogen, coal gas, or water gas, the gas is adsorbed on the deposited metal and immediate reaction with oxygen from the air ensues. K h e n as little as 4 X gram of platinum, 1 X 10-8 gram of palladium, 1.8 X lo-’ gram of iridium, or 2 X 10-8 gram of rhodium is present, a glowing spot is produced owing to the heat of reaction on the metal surface, larger amounts of metal may lead t o the ignition of the adsorbed gas. T h e test is meaningful historically, and because the only interference of importance is the reduction of test sensitivity caused by large amounts of arsenic or silver which act to poison the catalyst, it indicates the sensitivity and selectivity often associated with such reactions. 4 year before the appearance of the article by Curtman and Rothberg, Zenghelis described a test which also depended on t h e activation of hydrogen on the surface of platinum metals. Zenghelis noted (145) t h a t hydrogen can be detected by adsorbing the gas on palladium or platinum, where, upon the addition of soluble molybdates, i t will react to give an immediate blue color. Although it is difficult to single out a reaction t o be used as a preferred example, the test for gold described by Krumholz and Watzek (85), which is capable of disclosing as little as 2 X lo-“ gram of this metal, might be cited as a good illustration of the extreme sensitivity obtainable by both catalyzed and by induced reactions: T h e reaction used is the reduction of silver salts with ferrous sulfate, the reaction being induced by gold. T h a t catalytic tests can be highly selective or specific seems often t o be overlooked. T h e catalytic test for selenium proposed by Feigl and West ( 4 7 ) , for example, has real specificity, even interference resulting from the presence of sulfur has been obviated by properly conditioning the test reaction.
Theories applying to catalyzed and induced reactions are still in a nebulous state. Kolthoff and Livingston ( 1 9 ) have summarized the general theories of catalysis and induction, and Feigl has presented (SO) a most authoritat,ive review of the principles and implications of such reactions. Catalyzed Reactions. Catalyzed reactions are identified as those in which a given reaction velocity is enhanced, without shift of equilibrium position, by the presence of some “indifferent” agent. Catalytic activity often occurs, with the formation of a complex intermediate. For example, one of the most characteristic tests for the detection of sulfides is the sodium azide test described by Feigl ( S I ) . T h e activation of the reaction between azides and iodine is probably brought about by the formation of intermediate iodine-sulfur compounds ( 3 0 ) which immediately react with sodium azide with consequent release of the sulfur in its original form.
s-- + 12+ [ I . .. . S
. , . . I]-2NaN3
. . . . I]-+ 2NaN3 +2XaI + 3N2 + S--
+
[ I . ,. . s
12
+2NaI + 3N1
T h e catalysis is characteristic of both organic and inorganic sulfides, whereas corresponding telluriunl and selenium compounds are without activity. Sulfur in the form of sulfates, sulfites, or free sulfur is without distinguishing action. An interesting aspect of the sulfide catalysis is the implication of surface activity, as indicated by the reactivity of sulfide combined in such extremely insoluble forms as mercuric sulfide and arsenic sulfide. Even sulfide tarnish on silverware can be disclosed by the nondestructive sodium azide-iodine test. The possibility oi direct complex catalysis has been shown recently by Feigl and West ( 4 7 ) , where the role of the complex selenium-sulfide ion in the catalysis is clearly indicated by inspection of the individual reactions involved. The fundamental reaction is taken as the reduction of methylene blue (LIB) t o the leuco methylene blue (HMB) by alkali sulfides, the free sulfur
2MB
+ S-- + 2H20 --+-2HMB + So + 20H-
(1)
produced being inimediat,ely dissolved through the formation of the homoatomic complex, [S-So]--. I n cases where the homoatomic “polysulfide” complex is used as the initial reducing agent, higher reaction rates are obtained, which is to be expected, inasmuch as the polysulfides are generally considered as superior reducing agents. If, instead of the complex [S-So]--, the corresponding selenium complex with sulfide is produced,
S-- + SeO 176
+ [S-Seo]--
(2)
V O L U M E 23, N O . 1, J A N U A R Y 1 9 5 1 a still greater activity is obtained. Berause amounts of selenium as small as 0.08 microgram increase the rate of sulfide reductipn of methylene blue, it is apparent t h a t i t acts preferentially, in spite of tremendous escesses of sulfide ion. Where selenium is present the reaction should be
2X1B
+ [S-Seo]-- + 2H,O +2HMB + SeO + So + 20f1-
(3) with the st~leniuniand sulfur produced being rcdissolvetl hy excess respectively. T h e sulfide to form [S-Se”]-- and [S--SO]--, selenium reacts as, and is regenerakd to the form of, the comples and is therefore a comples catalyzer. I n the foregoing discussion the function of free sulfur was not mentioned. From t h e standpoint of the selenium test, possible interferenre from sulfur is prevented b y complesing the sulfur as the thiosulfate-the roniparative instability of the corresponding selenosulfate permits the selenium t o react with its usual effectiveness. . h o t h e r interesting observation in connection with the activity of polysulfides is the self-generation of catalyst according to Equation 1. Catalytic activitj- not, only is associated with coordination compounds, b u t may also be produced b y compounds showing ordinary valence relationships. X b ~ l( 1 , 3) h:is shown that hydrogen pcvosido normnlly oxidizes sodium thiosulfate t o form the tetrathionatc in the presence of iodides as the catalJst. If molybdate is usctl as the catal>.rt,however, the thiosulfate osidation is modified and the reaction proceeds t o thc formation of sulfate. E’eigl has shown ( 3 2 ) that similar diverting of this reaction occurr i n the presence of ot1lc.r 1)(.r:witl formers such as tungstates and van:idates. T h a t the formation of sulfates in these cases is not merely :i sccondary osidation b u t is actually a distinct diversion of thc: course of reaction is shown hj- the fact t h a t hydrogen perositle i i i t h e presence of molybdate, tungst:ite. or winatlate does not react with tetrathionak. Induced Reactions. Induced reactions may be considered as a special type of catalysis in which reactions arc activated, or reaction rates increased, b y a supposedly unrelated substance rearting independently within a common system; the inducing reaction may take place simultaneously with, or immediately befort,, the induced process. The net process ordinarily involves two separate reactions, the primary and the secondary, which have one common participant, the actor. Encountering induced reactions is a commonplace experience of all who work in the field of analytica.1 chemistry-for esample, copreripitation phenomena are very ofteii :tssociated with such reactions. Fresenius, in 1891, pointed out ( 5 3 ) t h a t while c:~lciunlhy itself does not precipitate from dilute solution as the sulfate, calrium sulfate will always b e “carried down” when even small concentrations of it are present during the precipitation of barium n i t h sulfuric :wid. Also, in spite of the fact t h a t pure calcium sulfate is reasonably soluble in water or sodium thiosulfate, the coprecipitated calcium sulfate resists all solvent action of these materials. Ah inkresting addition t o these ohservations is the work of van’t Kruys (86), who points out t h a t coprecipitation of calcium with barium as the sulfate prevents the coprecipitation of iron or cobalt which would ordinarily he carried down in very considerable amounts. I t is not to be implied t h a t all induced reactions are deleterious. T h e application of coprecipitat’ionin “gathering” minute amounts of material from gross samples is of estreme value in trace analysis. h recent esample is the collection of traces of gold, which is accomplished ( 1 1 7 ) tij- adding tellurium tetrachloride t o the solution t o be analyzed and precipitating the elemental tellurium with stannous chloride. As little as 0.1 p . p m . of gold can be collected from 1-gram samples in this manner, which makes possible subsequent colorimetric analysis. General Classification of Reactions. T h e preceding paragraphs have dealt with the nature of both catalyzed and induced reactions. A further classification of various reaction types can also be established which should serve for identification and characterization purposes.
177 Class I reactions would be those involving oxidation-reduction catalysis. -4classic example of such reactions is the catalytic decompo.qition of hydrogm peroside by the iodine-iodide couple. Liebhafsky has disclosed ( 9 d ) t h a t t,he rate-determining steps in this case are IOarid
I-
+ HZO? --+
H20
+ I - + 0,
+ H?O?--+H I 0 + H20
with the I O - and H I 0 esisting in rapid equilibrium with each other and with iodine. T h e majority of tests used in analytical work fall in this class. Induced precipitations can be designated as Class I1 reactions. This is a very important group because it includes coprecipitation, which is so important i n the use of gathering agents for the concentrating of traces of materials. T h e deleterious role, of coprecipitation in gravimetry need not be discussed here. For Class 111, it, is suggested t h a t “coupled reactions” he designated as :t separate class, although they can be properl!~ corisidered within the major group of general induced reactions. T h e purpose of including such a subgroup is to separate induced effects pertaining t o homogc,neoiis solutions. For esarnple, Tananaev ( 1 2 7 ) has shown t,hat neither osalic acid nor indigo is osidizeti by dichromates, under certain conditions, but when mist.ures of the two substances are treated with dichromate, both are oxidized. C l a ~ sIV reactions are those which involve heterogeneous catulysis. CATALYZED AKD INDUCED REACTIOKS IN QUANTITATIVE MICROANALYSIS
Catalytic efects are used advantageously in quantitative cheiiiiral analysis, particularly in titrimetry, where sluggish reactions are often accelerated t o make direct titrations possible; a classic esample of this is the titration of arsenities with ceric sulfate, in which trnces of iodides or osmium must be added in order t o rttalyze the reaction. C:ttalytic methods are also very useful in the deterniination of traces of material through quantitative measurement of reaction rates, because the velocity of reaction is often a direct function of the concentration of catalyst. Handell and Kolthoff (118) have described a chronometric niethotl for determining small quantities of iodine. T h e reaction 2 c e t + + - + & A + - ----f 2 C e + “ - + &is*&+-+ is catdyzed by iodides, so t h a t by noting reaction times it is possible t o estimate amounts of iodide t h a t may b e present. Chlorides and bromides do not interfere. O m i u m reacts in a manner similar t o iodide, b u t it is the only known interference, with the possible rxcept,ion of ruthenium ( 6 6 ) . Goto has made a number of studies (.59-6d) of catalytic methods of analysis, including procedures for iodine, silver, and copper, and sulfide, thiosulfate, and thiocyanate. Probably more important than the direct applications t o quantity measurement are the uses of catalj-zed and induced reactions as analytical aids. T h e induced precipitation of traces of mat,erials is widely used for gathering operations prior to final determination of quantity. CATALYZED AND IXDUCED REACTIONS IN SPOT T E S T ANALYSIS
I n general, the utilization of induced reactions i n spot test procedures involves the formation of abnormal colors of p r e c i p h t e s through coprecipitation or the production of easily discernible precipitates formed only as the result of the intiucing action. From the standpoint of spot test application, the isomorphous precipitates obtained by reaction of such metals as zinc, copper, nickel, and cobalt with mercuric thiocyanate compleses are of interest. Montequi (99) observed t h a t zinc reacts wit,h tetrathiocyanatoniercuroate t o give heavy white precipitates of
ANALYTICAL CHEMISTRY
178 Zn[Hg(NCS)a], but t h a t the presence of w e n minute quantities of copper causes the precipitate to be tinted violet due to the formation of Zn(Cu) [Hg(SCS)4]. IrIontequi’s observations have been extended by many other investigators, and spot tests for a number of metals are based on these reactions. The novel behavior encountered in such reactions is emphasized by Krumholz and Sanchez ( 8 4 ) )n.ho point out t h a t the formation of Co[EIg(NCS)1] takes place slowly and incompletely in dilute solutions, b u t in the presence of even a trace of zinc the cobalt is completely and immediately precipitat,ed, the blue color of t,he precipitate serving as a means of identifying zinc. Although the inducing reaction is considered to be t h e formation of Zn [Hg( S C S ) , ] , concentrations of zinc so small t h a t there is no visible evidence of zinc precipitate are still effective. The detection of titanium or zirconium by means of induced precipitation with arsenic acid has been studied by Feigl and Rajmann (45). Very dilute solutions of either zirconium or titanium fail to give visible reactions wit,h the arsenic acid, but, upon addition of traces of the missing element immediate precipitation occurs. Oxalic acid can be detected by its inducing action on the dichromic acid oxidation of indigo (1%’); this usually slow reaction is greatly accelerated by even traces of oxalate. The activity of the oxalate ion is also utilized in a test for manganese as described by Oberhmser and Ychormuller (104). Feigl and Krumholz (45)have developed a spot test for bismuth t h a t was originally thought to depend on the induced reduction of lead. Alkaline solutions containing lead react very slowly with alkaline stannite solutions. Na2SnOp
+ Ph(OH)2 +Pbo + Sa2SnOI + K O
Deposits of lead appear after long standing in simple mixtures of the reactants, but in the presence of even traces of bismuth salts, an immediate reduction of lead occurs. T h e effect of b i 5 muth is possibly due to the inducing action of the reaction,
3Na2Sn02
+ 2Bi(OH)8 +2Bi0 + 3Na2Sn08 + 3H20
although it is now thought probable by Feigl t h a t a catalytic reaction is involved which depends on the formation of lower valent salts of bismuth. Bi(II1) Bi(1)
+Bi(1)
+ P b ( I 1 ) +Hi(II1) + Pb(0)
which react with lead and are regenerated to the original t’rivalent state. The detection of copper by catalysis of the reaction between ferric salts and thiosulfates is important,. T h e primary reaction, 2Fe+++
+ 2S203-- ---+2 F e + + + Saos--
can be followed by use of thiocyanates to indicate the presence of ferric ion, and the addition of as little as 0.2 microgram of copper exerts a distinct catalytic effect, as evidenced by the fading of the red color of ferric thiocyanate (66). This catalytic effect can be attributed t o the reduction of copper by the thiosulf:tt.e, followed by reoxidation of the cuprous ion by the ferric iron. Many other spot tests are known t o be based on catalyzed and induced reactions, but it is not possible to consider all of them in this discussion. Reference to Feigl’s books (28-50) will disclose the scope of such techniques, and it is suggested t,hat thcw worlts be consulted for further information. BIBLlOGRAPIIY
(1) Abel, E., Z . Elektrochem., 18, 705 (1912). Selective catalytic re-
actions. (2)Ibid., 19,933 (1913). Catalysis. (3)Abel, E.,Monatsh., 34, 821 (1931). Catalytic studies. Hydrogen ion catalysis and autocatalysis of catalytically dlverted hydrogen peroxide-thiosulfate reaction. ( 4 ) Zbid., 68, 387 (1936). Kinetics of oxidation of ferrous ion by nitric acid.
(5) Bancroft, W. D., J . Phys. Chem., 33, 1185 (1929). Classification of induced reactions. 46) Berg, P. V., Z . anal. Chem., 25,512 (1886). Separation of zinc from iron, cobalt, and nickel. (7) Berglund, E., Ibid., 22,184 (1883). Separation of copper and zinc by hydrogen sulfide. (8) Blaser, Bruno, and Halpern, Paul, 2. anorg. u. allgem. Chem., 215, 33 (1933). Oxidation of hypophosphoric acid by bromine. (9) Bobtelsky, &I., Ibid., 189, 196 (1930). Chlorine generation from concentrated hydrochloric acid in presence of complex catalysts. Potassium chromate as oxidizing agent. (10) Bobtelsky, RI., and Chajkin, L., Ibid., 209,95 (1932). Chemical reactions in concentrated electrolytes. Reaction .between vanadic and hydrobromic acids and effect of acids, salts, and catalysts. (11) Bobtelskv. M.. and Czosnek. S.. Ibid., 206,113 (1932). Theory and piactice of complex catalysis. Effect of complex catalysis upon vanadic acid reduction with concentrated hydrochloric acid. (12) Bottger, W., Z . angew. Chem., 38,802 (1925). Concentration precipitation from induced precipitation. (13) Bottger, W.,and Druschke, K., Ann., 453, 315 (1927). Examples of induced precipitation. (14) Bottger, IT., and Thoma, E., J . prakt. Chem., 147, 11 (1936). Clarification of Wicke reaction. (15) Brauner, Bohuslar, and Kurzma, Bohumil, Ber., 40, 3362 (1907). Separation of tellurium from heavy metals and formation of a copper acid. (16) Bruner, L., and Zawadski, J., 2. anorg. u. allgem. Chem., 65, 136 (1909). Equilibria in precipitation of metals by hydrogen sulfide. (17) Bruni, Giuseppe, and Padova, Maurice, Atti reale accad. Lincei, 14, 525 (1905). Conditions of precipitations and of solutions of metallic sulfides. (18) Criegee, Rudolf, Ann., 522, 75 (1936). Osmic acid esters as intermediate products in oxidation. (19) Curtman, L. J., and Rothberg, P., J . Am. Chem. Soc., 33,718 (1911). Application of the glow reaction in qualitative detection of platinum metals. (20) Czerwek, A., 2. anal. Chem., 45, 505 (1906). New method for separation of antimony and tin. (21) Dahr, N. R., Sen, K., and Chatterji, N., Kolloid-Z., 33, 29 (1923). Studies in adsorption. Adsorption of compounds and quantitative analysis. (22) DenigBs, G., Bull. S O C . chim., 51, 1096 (1932). Catalysis applied to identification of certain cations. Case of silver and copper. Applications. (23) DenigBs, G., Mikrochemie. 4, 149 (1926). Utilization of catalysis in microcrystalline analysis (for detection of hydrooyanic acid). (24) Evans, B. S., Analyst, 56, 171 (1931). New method for reduction of tin and antimony prior to titration. (25) Feigl, F., Chem. Weekblad, 27,110 (1930). Use of complex and catalytic reactions in analytical chemistry. (26) Feigl, F., J . Chem. Education, 20, 137 (1943). Spot-reaction experiments. Catalytic reactions. (27) Ibid., 22, 36 (1945). Spot reaction experiments. Catalyzed reactions brought about by photolysis of ferric oxalate. (28) Feigl, F., “Manual of Spot Tests,’’p. 157, New York, Academic Press, 1943. Tests by catalytic reactions. (29) Feigl, F., “Qualitative Analysis by Spot Tests,’’3rd ed., p. 107, New York, Elsevier Publishing Co., 1946. Test by activation of chlorate solutions. (30) Feigl, F., “Specific, Selective and Sensitive Reactions,” p. 122, New York. Academic Press, 1949. Catalyzed and induced reactions. (31) Feigl, F., Z . anal. Chem., 65, 25 (1924). Coordination studies of analytical behavior of heavy metal sulfides. (32) Ibid., 74, 369 (1928). New and sensitive method for detection of sulfides and sulfates. (33) Ibid., p. 376. Analytical utilization of catalysis produced by carbon disulfide for iodometric determination of azides and for detection of carbon disulfide. (34) Feigl, F., 2. angew. Chem., 43, 550 (1930). Evaluation of adsorption-phenomena in qualitative analysis. (35) Ibid., 44,739 (1931); Mikrochemie (2), 4, 296 (1931). Catalysis and microchemistry. (36) Feigl, F., Z . anorg. allgem. Chent., 157,251 (1926). Coordination studies of analytical behavior of heavy metal sulfides. (37) Feigl, F., and Badiak, L., in “Qualitative Analysis by Spot Tests,” 3rd ed., p. 52, New York, Elsevier Publishing Co., 1946. Test by catalytic acceleration of reduction of tin(1V) salts. (38) Ibid., p. 53. Test by activation of aluminum.
V O L U M E 23, N O . 1, J A N U A R Y 1 9 5 1 (39) Feigl, F., and Braile, Nicolau, Chemist-Analyst, 33, 76 (1944). Application of spot reactions. Identification of CaSO4. (40) Feigl, F.,, and Chargav, E., 2. anal. Chem., 74, 376 (1928). Analytical utilization of a catalysis produced by carbon disulfide for iodometric determination of azides and detection of carbon disulfide., (41) Feigl, F., and Frank, G., in “Qualitative Analysis by Spot Tests,” 3rd ed., p. 345, New York, Elsevier Publishing Co., 1946. Test by catalytic acceleration of oxidation of pphenylenediamine by hydrogen peroxide. (42) Feigl, F., and Frankel, E., Ber. 65B, 540 (1932). Analytical utilization of catalytic reactions. (43) Feigl, F., and Krumholz, P., Ibid., 62B, 1138 (1929). Analytical utilization of complex chemical and induced reactions. (44) Ihid., 63B, 1917 (1930). Analytical application of catalytic reactions. Characteristic test for palladium. 145) Feigl, F., and Rajmann, E., Mikrochemie, 19, 60 (1935). Use of induced precipitation. (46) Feigl, F., and Uzel, R., Ihid., 19, 132 (1936). Qualitative microanalysis. (47) Feigl, F., and West, P. W.,- 4 s ~CHEM., ~. 19, 351 (1947). Test for selenium based on catalytic effect. (48) Fenton, H. J. H., and Jones. H. O., Proc. Chem. Soc., 15, 224 (1899). Oxaloacetic acid. Oxidation of certain organic acids in presence of ferrous salts. (49) Filimonovich, K. hI., Ukrain. Khem. Zhur., 5, Sci. Pt., 383 (1930). Microchemical reactions for copper. (50) Follenius, F., Z . anal. Chem., 13, 411 (1874). Methods of estimating cadmium. (51) Freidmann, E., J . prakt Chem., 146, 179 (1936). Sulfhydryl compounds as catalysts for decomposition of sodium azide by iodine. (52) Fresenius, K., Z . anal. Chem., 1, 444 (1862). Good reaction with antimony. (53) Ihid., 30, 452 (1891). Separation of barium from calcium. (54) Funk, W. Z., Ihid., 46, 93 (1907). Separation of zinc from nickel, cobalt, iron, and manganese by means of hydrogen. (55) Gaze, R., Apoth. Ztg., 27, 959 (1912). Estimation of platinum as sulfide. ( 5 6 ) Gleu, Karl, 2. anal. Chem., 95, 305 (1933). Osmium tetroxide as catalyst for oxidation of arsenious acid by permanganate and ceric sulfate. (57) Glixelli, Stanislaus, 2. anorg. Cheni., 55, 297 (1907). Precipitation of metals by hydrogen sulfide. Action of hydrogen sulfide on zinc salts. (58) Gluud, W., and Schoonfelder, R., Be,., 57B,628 (1924). Nickel sulfide. (59) Goto, Hidehiro, and Eudo, Eniico, J . Chem. Soc. J a p a n , 64, 509 (1943). Catalytic analysis. hIicrodetermination of silver and copper by Pulfrich photometer. (60) Goto, Hidehiro, and Hakamori, Emikeo, Ibid., 63, 1324 (1942). Catalytical analysis. Mcrodetermination of iodine with Pulfrich photometer. (61) Goto, Hidehiro, and Shishiokawa, Takanobu, Ibid., 65, 673 (1944). Catalytic analysis. hficrodetermination of sulfide, thiosulfate, and thiocyanate with fluorescent indicators. (62) Goto, Hidehiro, and Tachiyo, Kakita, Ibid., 66, 39 (1945). Catalytic analysis. (63) Haber, Fritz, and Bran, Fr., 2. physik. Chem., 35, 81 (1900). Autoxidation. (64) Hahn, L., Ber., 65B, 840 (1932). Catalytic detection of silver in extremely dilute solutions (lecture experiment). (65) Hahn, L., Mikrochemie, 8, 77 (1930). Microcatalytic detection of platinum metals. (66) Hahn, L., and Leimbach, G., Ber., 55B, 3070 (1922). Peculiar catalytic reaction for detection and determination of copper and for lecture experiment. (67) Hawley, L. F., J . A m . Chem. Soc., 29, 1011 (1907). Chemistry of thallium. (68) Hofmann, K. A., Ber., 45, 3329 (1912). Carrying oxygen by osmium tetroxide and activating of chlorate solutions. (69) Hofmann, K. A., Ehrhart, O., and Schneider, Otto, Ihid., 46, 1657 (1913). Activation of chlorate solutions by cadmium. (70) Hoffmann, L., and Kruss, G., Ann., 238, 66 (1887). Quantitative determination of gold and its separation from platinum metals. (71) Ivanov, V. N., J . Russ. P h y s . Chem. Soc., 48, 527 (1916). New method of precipitating platinum sulfide and analysis of platinized asbestos. (72) Jannasch, Paul, and Ruhl, Friedrich, J . prakt. Chem., 72, 1 (1905). Separation of iron from manganese and magnesium, and of aluminum and chromium from manganese, zinc, nickel, and magnesium by hydroxylamine in ammoniacal solution. (73) Jellinek. K., and Czerwinski, J., 2. physik. Chem., 102, 438
179 (1922). Dissociation of hydrogen sulfide, sodium sulfide, and sodium hydrogen sulfide in aqueous solutions. (74) King, W. B., and Brown, F. E., IND. ENG.CHEM.,ANAL.ED.,5 , 168 (1933). Modification of Bettendorff’s arsenic test with adaptation for mercury determination. ( 7 5 ) King, W. B., and Brown, F. E., J . Am. Chem. SOC.,61, 968 (1939). hlodification of Bettendorff’s arsenic test. Catalyzed by mercury. ( 7 6 ) Knoche, Hedwig, Kolloid Z., 67, 195, 307 (1934). “Induced“ solubility of ferric hydroxide and several hydroxides in caustic liquor in presence of chromic hydroxide. (77) Ibid., 68, 37 (1934). “Induced” solubility of ferric hydroxide and several other hydroxides in caustic solutions in presence of chromium hydroxide. (78) Kolthoff, I. M., and Dijk, J. Van, Pharm. Weekblad, 59, 1351 (1922). Carrying donm of zinc by copper sulfide. 179) Kolthoff, I. M., and Livingston, R. S., ISD.ENG.CHEY.,ASAL. ED.,7,209 (1935). Catalytic and induced reactions in niicrochemistry. ;SO) Kolthoff, I. bI., and Pearson, E. A . , J . P h y s . Chem., 36, 540 (1932). Promoting action of copper sulfide on speed of precipitation of zinc sulfide. So-called coprecipitation of zinc with copper sulfide. (81) KomarovskiY, A. S., and Kasarenke, V. A , , 2. anal. Chem., 104, 413 (1936). Detection of Oxalate ion by decolorization of indigo solution according to Tananaev and Budkevich. (82) Komarovskii, A. S., and Shapiro, M.I., Mikrochim. Acta, 3, 144 (1938). Sensitive catalytic test for columbium and tantalum. (83) Rorenman, I. M., Z . anal. Chem., 95, 44 (1933). Increasing sensitivity of microchemical test for cobalt and copper and induced test for ferrous iron, ferric iron, and nickel. (84) Krumholz, P., and Sanchez, I-.,Nikrochemie, 15, 114 (1934). Detection of zinc by an induced precipitation. (85) Krumholz, P., and Watzek, H., Mikrochim. Acta, 2, 80 (1937). Catalytic action of gold in reduction of silver salts. (86) Kruys, h l . van’t, 2. anal. Chem., 49, 393 (1910); Chem. W e e k blad., 6, 735 (1909). Estimation of barium sulfate in presence of interfering substances. (87) Kiihnel-Hagen, S., Mikrochemie, 20, 180 (1936). Detection of small quantities of platinum in minerals, alloys, residues, etc. Separation and concentration of platinum by coprecipitation with tellurium. (88) Lang, Rudolf, Ber., 60B, 1389 (1927). Catalytic action of silver chloride in oxidation-reduction process. (89) Lang, Rudolf, Z. anal. Chem., 85, 176 (1931). Cse of iodine catalyst in titration of arsenious acid with permanganate. (90) Lang, Rudolf, 2. anorg. u. allgem. Chem., 152, 197 (1926). Catalysis of reaction between arsenious acid and permanganic acid and its application in analytical chemistry. (91) Ihid., 158, 370 (1926). Rapid method for determination of manganese a s permanganate. (92) Liebhafsky, H. A,, J . Am. Chem. Soc., 54, 1792 (1932). Catalytic decomposition of hydrogen peroxide by iodine-iodide couple a t 25’. (93) Loczka, J., Magyar Chem. Folybirat, 3. Behavior of thallium in acid solution toward hydrogen sulfide in presence of arsenic, antimony, and tin. (94) Lucas, R., Chem.-Ztg., 58, 889 (1934). Catalysis in applied chemistry. Catalysis in analysis and plant control. ‘ (95) hlanchot, Wilhelm, A n n . , 325, 93 (1902). Theory of oxidation processes. (96) Marshall, Hugh, Chem. h‘ews, 83, 76 (1901). Detection and estimation of minute quantities of manganese. (97) lfarshall, Hugh, Proc. Roy. Soc., Edinburgh, 23, 163 (1900). Action of silver salts on ammonium persulfate solution. 198) Meigen, W., and Schnerb, J., 2.angew. Chem., 37, 208 (1924). Oxidation of tartaric acid with potassium permanganate and hydrogen peroxide. (99) lfontequi, R., Anales SOC. espaA. fis. y qutm., 25, 52 (1927). Xew reactions of zinc, copper, and cadmium. Practical and theoretical study. (100) Xoser, L., and Behr, X I . , Z . anorg. u. allgem. Chem., 134, 49 (1924). Determination of metals of ammonium sulfide group by hydrogen sulfide under pressure. (101) \loser, Ludwig, and Graber, Hans, Monatsh., 59, 61 (1932). Determination and separation of rare metals from other metals. Determination of rhodium and its separation from platinum and other metals. (102) Maser, L., and Xiessner, >I., Z . anal. Chem.. 63, 240 (1923). Use of hypophosphorous acid in gravimetric analysis. Determination of mercury, gold, and palladium and their separation from other metals. (103) Oberhauser, F., and Hensinger, W.,Ber., 61B, 521 (1925). Activated form of oxalic acid. (104) Oberhauser, F., and Schormiiller, J., Ann., 470, 111 (1929,. Active molecule of oxalic acid.
180
ANALYTICAL CHEMISTRY
(105) Oberhelman, G. O., Am. J. Sci., 39, 530 (1915). Estimation of pentavalent vanadium by sodium thiosulfate. (106) Oudemans, A. C., Jr., Z . anal. Chem., 6 , 129 (1867). Procedure for direct titration of iron by means of hyposulfates of sodium. (107) Paal, C., and Friederici, L., Ber., 64B, 1766 (1931). Action of sodium hypophosphite on aqueous nickel salt solutions. (108) Ibid., 6SB, 19 (1932). Action of hydrazine on aqueous solutions of nickel salts. (109) Pinkus, A., and Aronsfrau, Ch., Bull. soc. chim. Belges, 41, 549 (1932). Titration of manganese by Proctor Smith process. (110) Pinkus, A., and Ramakers, L., Ibid., 41, 529 (1932). Titration of manganese by Proctor Smith process. (111) Quartaroli, A., IS Congr. intern. q u h pura aplicada, Madrid, 3, 223 (1934). Change (darkening) of cupric hydroxide in relation to tautomers of hydrogen peroxide. (112) Rao, G. G., Ramanjaneyulu, J. V. S., and Rao, V. M., Current Sci., 13, 319 (1944). Catalysis in volumetric analysis. (1 13) Hao, G. G., Ranian,janeyulu, J. V. S., and Rao, V. XI.,Proc. ,Yatl. Insl. Sczence, India, 11, 331 (1945). Catalysis in volumetric analysis. (114) Rossler. H., Chcm.-Ztn., 24, 733 (1900). Behavior of rhodium in alloys with noble~metals. (115) Ruff,O., Z . anorg. t i . ( i l l g e m . Chem., 185, 387 (1930). Studies in fractional precipitation. Influences of foreign substances in crystal lattice. (116) Ruff, O., and Hiruch, 13.. Ihid., 151,81(1926). Fractional precipitation. Carrying down. .ipparent contradictions of theoretical presumptions. Feigl’s hypothesis on sulfide formation. (117) Sandell, E. H.. ~ S A I . . CHEM.,20, 253 (1948). Colorimetric determinations of traces of gold. (118) Sandell, E. B., and Kolthoff, I. M.,J . A m . Chent. Soc., 56, 1426 (1934). Chronometric catalytic method for determination of micro quantities of iodine. (119) Sastri, B. N., and Yreenivasaya, hZ., Mikrochemie, 14, 159 (1934). Detection of enzymes by spot tests. (120) Schaer, Edward, Anu.,323, 32’(1902). Intensifying (“Activirende”) action of reducing agents, colloidal noble metals, alkaloids, and other basic substances for oxidizing agents. (121) Schmidt, E., and Tornow, E., Chem.-Ztg., 56, 187 (1932). Electrochemical detection of minute quantities of mercury. (122) Schonbein, C. F., J . p m k t . Chem., 89, 1 (863). Influence of sulfuric acid on lead salts. (123) Smith, G. McP.. J. An!. Chem. Soc., 39, 1152 (1917). Contamination of precipitates in gravimetric analysis. Solid solution and adsorption us. higher order compounds. (124) Storch, L., Bel... 16, 2015 (1883). Solubility of metallic sulfides in thio acids.
(125) Straumanis, AI., and Ence, E., 2. anorg. u. allgem. Chem.. 228, 334 (1936). System zinc mercuric thiocyanate-copper mercuric thiocyanate. (126) Tammann, G., 2. anorg. u. ollgem. Chem., 107, 1 (1919). Chemical and galvanic properties of mixed crystals and their atomic structure. (127) Tananaev, N.A., and Budkevich, A . A , , Z . anal. Chem., 103, 353 (1935). Detection of oxalate ion. (128) Tananaev, N.A., and Panchenko, G. A,, J . Russ. Phys.-Chem. SOC.,61, 1051 (1929). Detection of vanadium and tungsten. (129) Thiel, 9., and Gessner, H., Z . anorg. u. allgem. Cheni., 86, 1 (1913). Nickel sulfide and cobalt sulfide. Apparent anomalies in behavior of nickel sulfide with acid. (130) Thiel, A., and Ohl, H., Ibid., 61, 396 (1909). Precipitation of nickel sulfide from aqueous solutions. (131) Traube, W., and Lange, W., Ber., 58B, 2773 (1925). Contribution to knowledge of reduction-oxidation and autoxidation processes. (132) Treadwell, W.D., and Guitermann, K. S..2. anal. Chem., 52, 459 (1913). Separation of cadmium from zinc. (133) Usler, G., Ibid., 34, 391 (1895). Separation of mercury from metals of arsenic and copper groups. (134) Wicke, C., Z . Chemie, 8, 89 (1865). Xew degree of oxidation of nickel and its volumetric determination. (135) Ibid., p. 685. Catalytic conversion of sulfur dioxide into sulfuric acid. (136) Wieland. H., Ber., 45, 679 (1912). Combustion of carbon monoxide. (137) Wieland, H., and Franke, W.,Arm., 464, 101 (1928). Mechanism of oxidation processes. Activation of oxygen by iron. (138) Willard, H. H., and Young, Philena, J . A m . Chem. Sac., 50, 1322, 1368 (1928). Ceric sulfate as a volumetric oxidizing agent. (139) Wilm, T., J. Russ. Phus. Chem. Gesell., 1, 60 (1887). Qualitative separation of tin and mercury. (140) Wohler, L., and Metz, L., 2. anoru. u. allgem. Chem., 149, 297 (1925). Separation of platinum metals. (141) Wohler, L., and Spengel, A,, Z . a n a l . Cheni., 50, 165 (1911). Separation of platinum and tin. (142) Wohlers, H. E., Z . anorg. Chem., 59, 203 (1908). Adsorption phenomena of inorganic salts. (143) Woker, G., Ber., 47, 1024 (1914). Theory of oxidation enzymes, peroxides and catalase reactions of formaldehyde and acetaldehyde. (144) Voker, G., “Chemical Analysis,” Stuttgart, William Bottger, 1911. Catalvsis. Role of catalvsis in analvtical chemistry. (145) Zenghelis, C., Z ; anal. Chem., 49, 729 (1910). Sensitive rea;tion for hydrogen. RECEIVED June 28, 1950.
Medium for Assay of Vitamins with lactic Acid Bacteria LAURA 31. FLYKN, VICTOR B. WILLI.441S, BOYD L. O’DELL, AND ALBERT G. HOGAN University of Missouri, Columbia, Mo. The purpose of this work was to devise an easily prepared and flexible medium suitable for use in microbiological assays of several vitamins. This medium supports excellent growth of four bacterial species commonly used in assays (Lactobacillus casei, Streptococcus faecalis, Lactobacillus arabinosus, and Lactobacillus leichmannii). Growth responses can be measured either turbidimetrically or acidimetrically. The cultures containing only the crystalline vitamins grow in this medium at a rate comparable to that obtained in cultures containing extracts of natural materials. The curves for standard cultures and for unknowns are parallel straight lines when responses are plotted against doses on a log-log grid. One basal medium, with minor changes, can thus be used in assays of folic acid, riboflavin, nicotinic acid, and B I Z activity. The medium is easily assembled, because the constituents are available commercially, and only one adsorption, to purify the casein hydrolyzate, is required. Taken together
these advantages permit a marked saving of time, especially in a small laboratory that may be called upon to assay several vitamins more or less simultaneously.
A
RECEXT review by Snell ( 1 3 ) calls attention to the many
excellent methods which utilize microorganisms for vitamin assays. The multiplicity of methods, hoxever, complicates the management of a small laboratory which may make occasional assays of many different vitamins. The popular methods of assaying these vitamins prescribe different species of bacteria for each vitamin and each method specifies its own medium. Thus, technicians may spend a n inordinate amount of time preparing supplements and basal media of limited use. A medium capable of supporting optimum growth for various bacterial species and flexible enough t o be used for several vitamins would be markedly advantageous. Preferably, most of the constituents should be available commercially in dry form to simplify storage, a n d adsorptions, digestions, and purifications should be kept to a mini-
