ANALYTICAL CHEMIS’TRY
108 (195) Schreyer, J. M., and Ockerman, L. T., ANAL.CHEY.,23, 1312 (1951). (196) Schreyer, J. M., Thompson. G. W., and Ockerman, L. T., Ibid., 22, 691 (1950). (197) Ibid., p. 1426. (198) Schtitr, H., Fette u. Seifen, 51, 433 (1944). and Allen, E., ANAL.CHEM.,23,592 (1951). (199) Seaman, W., (200) Shlyapin, B. P., and Pevneva, 2. P., Zavodskaya Lab., 16, 661 (1950). (201) Sill, C. W.. and Peterson, H. E., ANAL.CHEM.,21, 1268 (1949). (202) Smith, F. W.,and Gardner, D. E., Arch. Biochem., 29, 311 (1950). (203) Smith, G. F., “Analytical Application of Periodic Acid and Iodic Acid and Their Salts,” Columbus, Ohio, ‘2. Frederick Smith Chemical Co., 1950. (204) Soibei’man, B. I., Zhur. Anal. Khim., 3, 258 (1948). (205) Sosnovskii, B. A , , Zavodskaya Lab., 16,872 (1950). ANAL.CHEM.,23, 1331 (1951). (206) Stanton, L. (207) Steinita, K., Mikrochemk urn. Mikrochem. Acta, 35, 176 (1950). (208) Stock, J. T., Metallurgia, 42, 48 (1950). (209) Stock, J. T., and Fill, M. A., Ibid., 41, 170 (1950). (210) Ibid., p. 239. (211) Stokowy, E., 2. Metullkunde, 41, 347 (1950). (212) Stone, H. W., and Eichelberger, R. L., ANAL.CHEM.,23, 868 (1951). (213) Swift, E. H., Arcand, G. M., Gutwack, R., and hfeier, D. J., Ibid., 22,306 (1950). (214) Syrokomskir, V. S., and Gubel’bank. S.M., Zhur. Anal. Khim., 4 , 146 (1949). (215) Ibid.,p. 203. (216) SyrokomskiI, V. S., and Knyareva, R. N., Zaeodskaya Lab., 16, 1041 (1950). (217) Syrokomskii, V. S., and Melamed, S. I., Ibid., 16,273 (1950). (218) Syrokomski:, V. S., and Silaeva, E. V., Ibid., 15, 1015 (1949). (219) Ibid., p. 1149. (220) Saabo, Zoltan G., and CsBnyi, Lhrl6, Magyar Chem. Folydirat, 56,112 (1950).
s.,
(221) Sznho, Z.. and Sugbr, E., . ~ - . A L . CHEM.,22,361 (1950). (222) Sreberhyi, Pbl, Magyar Kdm. Lapja, 4, 353 (1949). (223) Takagi, K., and Yamada, AT., J. Electrochem. Assoc. Japan. 18, 9 (1950). (224) Talpade, C. R., PTOC. Natl. Acad. Sci., India, 11A, 1 (1941). (225) Taylor, J. K., and Escudero-Molins, E., ~ ~ N . A I CHEM., .. 21, 1576 (1949). (226) Thornson. S. M., Ibid., 23, 973 (1951). (227) Tinsley. ,J., Taylor. T.G.. and Moore, J. H., Analyst, 76, 300 (1951). (228) Titova, Tu. G., Zhur. Anal. Khim., 6, 51 (1951). (229) Tomibek, O., Sandl, Z., and Simon, V., Collection (‘rrchoslov. (‘hwn. Communs.. 14, 20 (1949). (230) Trtilek, J., Chem. Listy, 38, 128 (1944). (231) Trump. W. S . , and Smith, L., Proc. Iowa A c a d . Sci.,55, 277 (1948). (232) Tsubaki, I., J. Chem. Soc. Japan, 71,454 (1950). (233) Urusovskaya, L. G., and Zhilina, P. I., Zaaodskaya Lub., 15, 740 (1949). (234) Usatenko. Yu. I., and Datsenko, 0. O., Ibid., 16, 94 (1950). (235) V&jna, S.,and Gabos-Pint&-, M., M a g y a r Chem. Foly6i~at,56, 63 (1950). (236) Vetrov, A. S., Zavodskaya Lab., 16, 362 (1950). (237) Vogel, H. C. v . , Arch. Eisenhiittenw., 20, 287 (1949). (238) Vorob’ey, A. S., Z h w . Anal. Khim., 4, 200 (1949). (239) Watson, J. P., Analyst, 76, 177 (1951). (240) Welte, H., Siiddeut. Apoth.-Ztg., 89, 698 (1949). (241) Weste, F., Arch. Metallkunde, 3, 147 (1949). (242) Whitnack, G. C., Holford, C. J., Gantr, E. St. C., and Smith, 0. B. L., ANAL.CHEM., 23, 464 (1951). (243) Wberlev. J. S.. Ibid.. 23. 656 11951). (244; Wi1lard:H. H., and Horton, C.~A.,Ibid., 22, 1194 (1950). (245) Wllson, A. E., Ibid., 22, 1571 (1950). (246) Wilson, H. N., Analyst, 76, 65 (1951). (247) Wogrinz, A., and Kudernatsch, G., Prakt. Chem., 1950, 197. (248) Zavgorodnii, S. F., Zavodskaya Lab., 15, 363 (1949). RECEIVED Sovember 12, 1951.
Volumetric Analytical Methods for Organic Compounds WALTER T. SMITH, JR., AND ROBERT E. BUCKLES State University of Iowa, Zowa City, Iowa
T
H I S discussion is based primarily on reports that have b e come available from September 1950 to October 1951.
DETERMINATION OF ELEMENTS HALQGENS
I n a new variation on the Parr bomb fusion a nickel bomb (with 0.3% manganese) of 10 ml. capacity is used. Eight drops of ethylene glycol and the sample are placed in the bomb and covered with 3 to 11 grams of sodium peroxide. The bomb is closed and heated with a microburner for 10 to 20 seconds t o ignite the mixture. After about 50 seconds of heating the bomb is quenched in water. One of the advantages claimed for this decomposition procedure lies in the fact that the bomb is not subjected to as severe service ae in the usual sugar-sodium peroxide procedure because the ignition temperature of the sodium peroxide-ethylene glycol mixture is 58” (161). However, it seems that this low ignition temperature constitutes a safety hazard, and care should be exercised in using this method. T h e following methods are used by Martin ( 9 4 ) for analyzing the decomposition products from the usual sodium peroxide Parr bomb fusion. The residue from the fusion is dissolved, boiled to decompose sodium peroxide, and treated with sufficient nitric acid to bring the concentration of the final solution to 25% nitric acid. Chloride is determined by the usual methods after bromine and iodine are removed by passing air or nitrogen through the solution. Bromide is oxidized b y sodium hypochlorite to bromate arid the excess hypochlorite is removed by the addition of sodium for-
mate The bromate is then determined iodometrically. This method cannot be used in the presence of iodide. Iodide is oxidiized by bromine water in neutral solution, and after the bromine is boiled off, the iodate is determined iodometrically. I n a combustion method a tube filled with quartz wool is used. T h e products of the decomposition are absorbed in a mixture of 3 ml. of Perhydrol and 7 ml. of water contained in a detachable s iral. T h e halide is determined argentometrically using dicborofluorescein indicator (46). T h e method of Freeman and ,1IcCullen (40)has been modified and subjected to collaborative study. T h e soniea hat variable results indicate that further study is necessary before the procedure can be recommended ( 1 4 2 ) . Two methods for the determination of halogens in halogenated fluoresceins (8, 6 7 ) have been studied collaboratively M ith satisfactory results ( 6 6 ) . Organic bromine compourids may be decomposed by treatment with lead-free zinc and 10% sodium hydroxide solution, followed by oxidation of the organic residue with permanganate ( 4 7 ) An alternative is to decompose a 3- to 4-gram sample by adding it to melted potassium. The ewess potassium is decomposed T\ith methanol and the methanol is removed by distillation (71). The analysis of fluorocarbons has been discussed in some detail. A combustion train is described which permits the determination of carbon, fluorine, and chlorine in a single sample if the sample contain. no hvdrogen (85). T h e determination of fluoride has been revieir ed n ith particular attention paid to the titration of fluosilicic acid tvith thorium nitrate using sodium alizarin sulfonate as indicator.
109
V O L U M E 24, NO. 1, J A N U A R Y 1 9 5 2 Colorimetric indicators for the titration of fluoride with thorium salts have been rated in the following order of decreasing effectiveness: purpurin sulfonate, Alicarin Red S, Eriochromecyanin R, dicyanoquinizarin, and Chromazurol S. The best fluorometric indicators are morin and quercetin. Optimum conditions include an alcohol concentration of 50% and a p H range of 3 to 4 (158).
I n a semimicroprocedure ($8)the sample is pyrolyzed a t 1050" to 1100" C. in a stream of oxygen-free nitrogen. The oxygen is converted into carbon monoxide by passing over carbon a t the same temperature, and the carbon monoxide is oxidized by mercuric oxide to carbon dioxide, absorbed in barium hydroxide solution, and determined titrimetrically. The method requires about 1.5 hours. The relative accuracy is 2%.
MERCURY
SULFUR
Mercury in organic molecules has been determined as follows (61).
A 3- to 5-mg. sample is placed in a Kjeldahl flask and 2 ml. of concentrated sulfuric acid containing 0.4 gram of potassium sulfate are added. The mixture is boiled gently for 20 to 25 minutes. The solut,ion is cooled and 5 drops of 30% hydrogen peroxide are added. The solution is boiled 10 t o 15 minutes, and the treatment with hydrogen peroxide is repeated. The solution is diluted with 15 ml. of water and the mercuric ion is titrated with ammonium thiocyanate by the Volhard method. NITROGEN
AIoelants has critically reviewed the combustion methods for the determination of nitrogen in organic compounds (103). A comhustion tube filling similar to that of Friedrich ( 4 1 ) but n.it,hout th(, lead dioxide is recommended. In ariother apparatus a combustion tube containing no lead dioxide is used and nitrogen and hydrogen are determined simultaneously by putting a water absorption tube between the combustion tube and the azotometer. Carbon may be determined in separate combustion using the same tube (162). Improvements for the Dumas method for nitrogen include a n electric furnace for automatic burning and an improved Kipp generator for generafing carbon dioxide free from air ($0). Ring nitrogen is not attacked in the Kjeldahl procedure if the compound is reduced by hydriodic acid and red phosphorus and then subjected to concentrated sulfuric acid, mercuric acetate, and potassium sulfate. The diffcrence between the result obtained in this way and that obtained by the Dumas method is a measure of the ring nitrogen in the sample (96, 97). The kinetics of the Kjeldahl determination on aniline have been studied using selenium, copper, mercury, and copper-niercury catalysts and also without catalysts. In all cases the reaction \vas first order with respect to aniline. The various catalysts were effective by different mechanisms (134). A systematic study of the effect of selenium oxychloride and potassium sulfate on the Kjeldahl determination of pyridine indicates that all the pyridine nitrogen is obtained by heating 0.15 gram of pyridine, 0.5 gram of selenium oxychloride, and 40 grams of potassium sulfate for 1 hour ( $ 3 ) . It appears that preliminary reducing treat'ment may not be necessary in the determination of nitrile-type nitrogen by the Kjeldahl method. In a wide variety of cases over 98% of the nitrogen was recovered when the reducing treatment was omitted (151). Several other variations on the Kjeldahl procedure have been reported (12, 48, 92, 113, 115). For the Dumas determination of nitrogen in compounds that are hard to burn completely it has been recommended that the sample be burned in a platinum boat with the help of copper oxide, in a stream of moist carbon dioxide and oxygen. The gas mixture is passed over heated copper a t the front end of the combustion tube to remove the excess oxygen and the nitrogen is collected in an azotometer over potassium hydroxide solution as usual (150). OXYGEN
Experiences during the past ten years in the use of the Cnterzaucher method (149) have been reviewed (150). A variety of thermal decomposition methods for the direct deterniination of oxygen in organic compounds has been discussed
(4).
I n a procedure for sulfur the sample is burned in a stream of oxygen and the escaping gases are brought into contact with a stream of hydrogen. In the hydrogen-oxygen flame hydrogen sulfide and a very little free sulfur are formed and are absorbed in strong sodium hydroxide solution. The sulfide and polysulfide thus formed are titrated oxidimetrically with standard hypochlorite solution. Since the valence change of the free sulfur is from 0 to 6 and the hydrogen sulfide from 2 to +6, the results are usually a little low (76). The use of the Zimmermann method (165) for determination of sulfur in sulfanilic acid, sulfanilamide, sulfathiazole, and sulfamerazine has been reported (58).
FUNCTION4L GROUPS ACETYL
The method described by Clark (22) has been modified for the determination of acetyl groups in pectin (114). Acetates of hydroxyethylcellulose have been saponified with aqueous-alcoholic potassium hydroxide solution to give saponification equivalents which become slightly lower with longer saponification periods (24). ACTIVE HYDROGEY
In a variation on the determination of active hydrogen, methyl magnesium iodide in ether is mixed with the sample in pyridine. The methane formed is forced into an azotometer by ether vapoi The ether vapor is absorbed in 50% aqueous alcohol in thc azotometer (117). In an elaborate lithium aluminum hydride method the sample is brought in contact a i t h a solution of lithium aluminum hydride in n-propyl ether. The hydrogen formed is carried bv nitrogen to a combustion tube containing cupric oxide a t 1100" to 1120", where it is converted to a ater. The n ater on contact with hot carbon is converted to carbon monoxide, which subsequently reacts with iodine pentoxide to liberate iodine. The iodine can then be determined by titration (132). ACIDS
A large variety of organic compounds may be titrated as acids with 0.1 N sodium methoxide in benzene-methanol if the proper nonaqueous solvent is employed (42). Most carboxylic acids can be titrated in benzene-methanol solutions. Acid chlorides and anhydrides may be titrated as strong monobasic acids in benzene or benzene-methanol. Enols cannot be titrated sharply iri benzene-methanol, but give good results in butylamine. Succinimide also behaves as a strong acid in butylamine. Nitromethane may be titrated in butylamine, but the results are low and erratic., perhaps because of partial decomposition. Butylamine serves as a suitable solvent for the titration of thiophenol and 2-mercaptobenzothiazole. Strychnine sulfate and @-bromoethylamine hydrobromide can be titrated in benzene-methanol. Hydroxylamine hydrochloride is insoluble in benzene-methanol, but may be titrated in pyridine. The end points are determined eithei potentiometrically or by use of thymol blue indicator. A modification of the bromometric method of hlaeder (86) for the determination of formic acid has been described (117). In a vapor phase study, acetic acid is condensed in a sample tube, sealed off, broken under carbon dioxidefree water, and titrated with standard barium hydroxide solution to a phenol red end point ( 1 4 6 ) .
A N A L Y T I C A L CHEMISTRY
110 dcetic acid arising from the alkaline cleavage of substituted acetylacetones has been determined in the presence of excess &diketone by a titration procedure. The thymol blue indicator used does not give too sharp an end point (111). Carboxyl end groups in polyaminocaproic acid have been dei termined by the following method.
A 100-mg. sample in 3 ml. of boiling p-phenylethyl alcohol is quickly diluted with 10 ml. of n-propyl alcohol-water azeotrope, and the indicator (120 mg. of phenolphthalein and 18 mg. of thymol blue in 1 liter of aqueous ethyl alcohol) is added. The solution is placed in a photometric colorimeter, stirred with nit,rogen gap, and titrated with 0.01 sodium hydroxide (131). ALCOHOLS
The formylating reagent of Glichitch (53) has been used recently for the determination of primary, secondary, or tertiary alcohols (128). It is necessary to carry out control runs along with the samples to be analyzed. T h e method presumably is valuable for determining alcohols that are easily dehydrated. The acetic anhydride-pyridine technique has been used to determine the equivalent weight (per hydroxyl) of hydroxyetlqdcelluloEe (34). ALDEHYDES AND KETONES
Carbonyl compounds have been determined in the foDmvirYg way. The sample is treated wit'h excess 2,4-dinitrophenylhydrazine and hydrochloric acid. The excess reagent is then treated with a known amount of t,it,anous chloride (12 moles of titanous chloride per mole of dinit,rophenylhydrazine),and the excess t,it,anous chloride is titrated wit,h ferric alum to a thiocyanate end point (138).
The hydroxylamine hydrochloride method of Bryant m d Smith (I?) has been used for the analysis of the combined i506ut~rrtfIdehyde and methyl ethyl ketone arising from the pinaco,l rearrangement of isomeric 2,3-butanediols ( 5 ) . In a kinetic study of the condensntion of aniline and substit,uted anilines with formaldehyde in aqueous hydrochloric acid, use has been made of the sulfite method for estimation of the total amount of formaldehyde, methylene aniline (C6H,S= CH?),and the cyclic trimer of methylene aniline ( 1 1 0 ) . Some previously described methods for furfural and pentosans (108, 109) have been reinvestigated and found useful (16). Furfural is determined by adding an alcholic solution of hydroxylamine hydrochloride and titrating the hydrochloric acid liberated with 1 K sodium hydroxide solution to a bromophenol blue end point. As pentosans and pentoses yield furfuraldehyde when suitably heated with hydrochloric acid, the method can be applied also to their determination. l'anillin has been determined by oxidizing the sample in 1 sodium hydroxide solution with hydrogen peroxide and titrating the excess alkali with 1 S hydrochloric acid to a phenolphthalein end point. A blank is necessary (138). A4ret,onehas been determined in the presence of di-tert-butyl peroxide by the method of Maltby and Primavesi (88). Their procedure has been modified by using only a 20 t'o 30% excess of hydroxylamine hydrochloride and by using a p H meter rather than an indicator for the end point (32). I n order to folloK the concentration of acetylacetone during basic ethanolysis, the following procedure has been used. The sample is added to 0.1 X acid and excess bromine lvater is added. After 4 minutes phenol is added, followed by potassium iodide. After 5 to 10 minutes the reaction mixture is titrated t,hiosulfate solution (112). Theoretically, 4 moles of with 0.1 thiosulfate should correspond to 1 mole of ketone, hut in actual practice t,he value was 3.77 (94%). This could he increased to 3.87 (97%) by increasing the contact time of the potassium iodide solution. a\7
AMINES
I n a study of the aminolysis of esters, a variety of amines were determined in the presence of esters by titration with aqueous
0.05 to 0.1 S hydrochloric acid to methyl red-methylene blue indicator. The following amines were used: n-butylamine, piperidine, morpholine, isobutylaniine, methyl-n-butylamine, and methylisobutylamine (10). Under proper conditions the action of nitrous acid on 1,4diphenylmediamine t o diazotize one amino group is quantitative and the reaction has been used for the determination of 1,4diphenylenediamine (139). The previously described procedure of Katanabe and Ishinose (155) for the determination of aromatic primary amines has been revised so that solid samples may be analyzed, and small amounts of reagents may be used (156). ii study has been made of the amount of nitrogen evolved when various heterocyclic amines are diazotized (146). Pyridine carboxylic acids dissolved in acetic acid have been titrated n i t h 0.1 A' perchloric acid in acetic acid using a methyl violet indicator. An end-point blank is necessary. The mean error is i1yo( 7 0 ) . Methods have been described for analyzing the basic products formed in the reaction between aqueous ammonium salts and formaldehyde ( 9 ) . The titration of weak bases with perchloric acid in acetic acid has been discussed (89, 156). Potassium acid phthalate is recommended as a primary standard (135). AZO GROUPS
1,1'-lzobis( 1-arylalkanes) have been shown to decompose quantitatively in ethylbenzene to yield nitrogen gas, which is snept by a current of carbon dioxide into an azotometer containing 40% potassium hydroxide and the volume is measured ( 2 3 ) . DI4ZO\IUM GROUPS
By measuring the amount of nitrogen evolved in the follon ing reaction ArS,CI
+ I - +ArI + Sr+ C1
aromatic diazonium salts have been determined. Saphthols may also be determined by coupling with an evcess of diazonium salt, folloned by determination of the excess by the above reaction. The methods are not very exact, but are said to be suitable for plant control work and cornparipon measurements (45). ESTER GROUPS
The determination of the saponification number of resins and other difficultly saponifiable esters is facilitated by use of a diethylene glycol solution of potassium hydrouide containing about 8% phenetole The phenetole increases the solvent power of the reagent and excludes atmospheric oxygen from the reaction mivture by providing a blanket of vapor over it (136). A solution of potassium hydroxide in a 1 to 1 mixture of Cellosolve and xylene is described as an ideal reagmt for determining saponification equivalents (64). HYDROX4hIIC ACIDS
Long-chain hydroxamic acids have been determined by hydrolysis with a known amount of hydrochloric acid in aqueous ethyl alcohol. The excess hydrochloric arid is titrated n i t h standard sodium hj-droxide. The results obtained are slightly low. An alternative procedure invclves titration of the hydroxylamine hydrochloride formed. This method gives results which are slightlx- high The hydrovylamine hydrochloride cannot be titrated in the presence of fatty acids containing ten or less carbon atoms (125). OXIRANE GROUP
Ethylene oxide reacts quantitatively with hydrochloric acid containing magnesium chloride or calcium chloride and the exress hydrochloric acid may be determined by titration
111
V O L U M E 2 4 N O . 1, J A N U A R Y 1 9 5 2 n ith standard base t o a methyl red end point. Pure magneduni chloride is essential. Calcium chloride gives a constant factor of 1.01 (101). This method is similar to the one of Lubatti ( 8 4 ) 15 hich has been used for the determination of ethylene oxide in mixtures containing acetaldehyde, formaldehyde, and acetic acid (104). I n a different procedure (34) a I-ml. glass bulb contairiing 0.1 to 0.2 gram of ethylene oxide is broken under the surface of a 1% solution of periodic acid in 4 S perchloric acid. After 45 minutes, the excess periodic acid is determined by a Ptandard method ( 6 3 ) . PEROXIDES
.Igain as last year anuniber of investicators have used iodometric methods for the analysis of various peroxides. I n general, either acetic acid or acetone has been used as a solvent. T h e decomposition of the peroxide by the iodide is carried out in the warmed solution in an atmosphere of carbon dioxide usually supplied by dry ice. Titration is n i t h standard thiosulfate. T h e use of acetone as a solvent is not wmplicat'ed by iodination under the conditions of the reaction. Such methods have been described for acetyl peroside ( f P 6 ) , lauroyl peroxide (ZO),substituted benzoyl peroxides (13, f @), tert-butyl perbenzoate ( 1 4 ) , peroxides formed during the autoxidation of benzaldehydes (1.54), and benzol-] peroxide in the presence of iodine, which must be removed by titration with thiosulfate before the determination is carried out ( 5 6 ) . SULFONA.1IIDE.S
Sulfonamides have becn determined by titration with lironiine in acetic acid in the presence of sodium acetate (31). 1 siniilsr approach has been the titration with sodium hypochlorite. T h e sulfonamide solution is kept basic so that the reaction olxei.vecl is: ItSOrSH.?+ NaOCl --+ RSOrSC:lSa H,O
+
T h e titration is carried out in the following fashion.
A weighed amount, of the sulfonamide is dissolved in warm sodium hydroxide solution. The solution is cooled t80 room temperature. diluted with water to 100 ml., and placed in a Dewar flask. The solution is stirred mechanically for 15 minutes. T h e standard sodium hypochlorite solution is then added slowly in 2-m1. portions at, first hut in smaller portions as the reaction progresses. After each addition the temperature, measured by a Beckmaii thermometer, is recorded as soon as it lieconies constant,, usually in shout. 30 seconds. h plot of volume of sodium hypochlorite solution added agaimt temperature yieids a line that is nrarl>- straight. d t the equivalence point a change in slope is oiiserved. Values obtained are accurate to about 1% (137). I n a general discussion of methods for sulfonamide analysis the volumetric methods are considered to be more accurate than the colorimetric methods. The nitrite titration to the starch-potassium iodide end point is believed the most specific. Other indicators are also discussed ( 2 ) . Uh-SATURATION
Analyws f o i , individual olrfiiis or grnrral deterniinatioii,~of unsaturation --e.g., the iodine numlwr-have been Carrie11 out most frrqurntly by bromine addition. Ethylene gas has bec~ridetermined by absorption in an excess of a solution of bromine in acetic acid followed by an iodometric titration of t h e excess bromine (100). Styrene and 0-methylstyrene have been determ i n d in iiiti.obenzene-carbon tetrachloride solution i n the presence of their polymrrs, stannic: chloride, and amines by direct titration ivith bromine in carbon tetrachloride (49, LO). Dienes have been similarly determined in acetic acid solutions containing potassium acetate by direct titration with hroniine in acetic acid (80). The method of Kaufniaiin ( 7 2 ) , which involves reaction with
bromine in methanol folloived by titration of the excess bromine x i t h arsenite solution, has been found more accurate than other methods for the determination of the iodine numbers of seveinl o , P unsaturated acids ( 1 2 9 ) . Similarly the iodine numbers of several phenols, cholesterol, limonene, naphthalene, oleic acid, and various essential oils have been determined in acetic acid soluliotl
(148). Kaufniann's reagent ( 7 3 ) )hron:itir in niethanol saturated n it11 sodium bromide, has been applied to the measurement of unsaturation in motor fuels (159). The objections of Joshel, Hall, arid Palltin (68) to the use of Iialogen in the determination of unsaturation in terpenes because of the ease of substitution are reported to have been overcome. The method is a modification of that of Francis (39) and is (wried out as follows ( 3 6 ) .
.I 1-ml. sample is placed i r i a glass-stoppered Erlenmeyer flask. A volume of 10% sulfuric acid about 1.5 times as large as the volume of bromide-bromate solution required (determined by a trial run) is then added. The 0.5 *V bromide-hromate solution (14 grams of potassium bromate and 50 grams of potassium bromide per liter) is added in 5-ml. portions a t first and in 0.5ml. portions toward the end of t,he determination when the react,ion slo\vs down. After each addition the flask is shaken vigorously until the color disappears. The reaction is considered to be complete when t8hecolor persists for more t.han 30 seconds. The addition of 5 ml. of 10% potassium iodide solution follo\ved by tit,ration n-ith 0.2 .Y .odium thiosulfate coiiipletes the determination, The method of Kemp and Mueller ( 7 5 ) for the deternkiation of unsaturation by the addition of iodine chloride has beeii applied to the analysis of polyisoprene, rubber, and gutta-ptwha. With chlorinated polymers the method must be inodifird in order to allow longer times for addition of the iodine chloride ( 7 8 ) . The volume of hydrogen taken up over palladium on charcoal has been used for the determination of the iodine numbrr of isomerized linoleic acid and its ester ( 1 0 7 ) . A similar determination capable of measuring the hydrosen uptalir of less t h n n 1 mg. of sample has also been described (98). The iodin? rquivalen ts of the diene numhrrs of dienes havc 11c~c11~ deteririnrtl by a modification of t h r method of Kaufmann and Bakes ( 7 4 j in Jvhich the diene rearts n.ith excess maleic anhytlyide in the prrsmce of iodine, n.hic,h catalyzes cis-trans isomerizatici11, The product is separatcd, and the excess anhydride is dctcrlni1le(l by titration (99). Tervinal triple bonds have heen determined by the rc.;ic.tio~~ in ncutral aqueous or a](, iholic solution \I ith silver h(>llzo:itc.. After filtration, titration of the arid giv1.s a measure of thc rlunitirr of t r m i n a l triple bonds (93).
3IISCELL.ANEOUS IIETIIODS LITHIUM DERlVATIVES
The concentrations of methyl lithium and phenyl lithiutii have been determined in n-butyl ether csontaining ethyl ether and nor fe/.t-butyl chloride by titration with 0.1 .Y hydrochloric. acid to the lacnioid end point. The determination was checked i t i the case of methyl lithium by the %erewitinoff-type determiti:itio~i of the methane formed (25, 26). !WERCURY DERIVATIVES
Sonlialogen mercurials whrn t r r x t r d \vith sodium chloi~itiogive compounds of the type I1HgCI. The exeess sodium c.hloritlc is determined by the Volhard method. With 3 compound of t h e type RHgR' a reaction with acetic acid is carried out to givc, t h e acetoxyniercuri compound, a.hich is thrn treated with sodium chloride as above. Similarly, a haloniercuri compound is first treated rvith moist silver oxide in alcohol to give the correspontling hytlroxyniercuri compound, Lvhich is then treated with sodium chloride ( 1 2 4 ) .
112 MIXTURES
Mixtures of hydrocarbons rontaining saturated, unsaturated, and aromatic hydrocarbons have been analyzed by selectively dissolving the unsaturated hydrocarbons in one reagent ( 5 grams of boric acid in 100 ml. of concentrated sulfuric arid) and the unsaturated and aromatic hydrocarbons in a second reagent (30 grams of phosphorus pentoxide in 100 ml. of concentrated sulfuric acid). The method is effective if no more than a maximum of 30% of the mixture is absorbed in a reagent. For cases in which more is absorbed, dilution with chloroform is suggested (152). Similar selective absorption has been used to determine the composition of mixtures of carbon disulfide, thiophene, and carbonyl sulfide. The thiophene is absorbed by 93% sulfuric acid, the carbon disulfide by 93% sulfuric acid containing spindle oil, and the carbonyl sulfide is obtained by difference (121). hlixtures of amines have been titrated 4 ith standard hydrochloric acid to obtain the total basicity of the mixture. A similar titration after acetylation with acetic anhydride gives a direct measure of the amount of tertiary amines. Titration of the mixture after reaction with salicylaldehyde measures the amounts of secondary and tertiary amines combined. The individual amounts of primary and secondary amines are then determined by difference (140). The Grignard reagent in mixtures of n-hexyl magnesium bromide and benzyl chloride has been determined by the method of Gilman (51 ), except that no heating is used. After the addition of cold water, standard acid is added, and the mixture is allowed to stand 1.5 hours. The excess acid is titrated with standard base. After the titration 50 ml. of 0.2 N sodium hydroxide are added, and the volume is made up to approximately 150 ml. After the addition of 60 ml. of 95% ethyl alcohol the solution is approximately 0.045 N sodium hydroxide in 27% alcohol. The mixture is boiled 30 minutes under reflux, and the excess alkali is titrated to give a measure of the amount of benzyl chloride present. A blank run is carried out. Results accurate to &2'% are obtained (130). Methanol in mixtures of methanol and ethyl alcohol has been determined in the following manner (144). A 3-ml. sample is diluted to 100 ml. with water. To a twocompartment flask connected to a gas buret, 4.0 ml. of the diluted sample are added, and 1.5 grams of potassium chromate are added to the same compartment. To the other compartment are added 6 ml. of 18 S sulfuric acid. The system is closed and the solutions are mixed. The volume of carbon dioxide evolved is measured. A correction is necessary for carbon dioxide evolved by ethyl alcohol under the reaction conditions. Mixtures of alcohols and amines obtained during the course
of alkylation of amines by alcohols have been completely acetylated. Saponification under suitable conditions gives negligible hydrolysis of the amides, so that the saponification equivalent is a measure of the alcohol content (141). A modified reagent containing cupric ion ahich oxidizes fructose selectively in the presence of glucose has been described. The cuprous oxide formed is dissolved in standard ferrous sulfate solution, and the excess ferrous sulfate is titrated with potassium permanganate solution. The combined fructose and glucose are oxidized by one of the standard reagents, and the amount of cuprous oxide formed is measured as above (11 ) . Mixtures of pinene and camphor have been treated n ith acetic acid containing sulfuric acid, formic acid, or formic acid containing acetic anhydride. In each case, camphor reacts to a greatei extent than pinene. The excess reagent is titrated. A plot of the amount of reagent used us. composition of known mixtures is necessary for each reagent (37). Mixtures of e-aminocaproic acid hydrochloride and hexamethylenediamine dihydrochloride from the hydrolysis of certain types of nylon polymers have been titrated directly with 0.1 N sodium hydroxide to the phenolphthalein end point to give a direct measure of the e-aminocaproic acid hydrochloride which acts as a monobasic acid. Treatment of the mixture of hydrochlorides
ANALYTICAL CHEMISTRY in aqueous solutiori with Amberlite IR.1-400 ion exchange resin gives hexamethylenediamine in solution, which is determined by titration with 0.1 iY hydrochloric acid to methyl orange ( 6 7 ) . Mixtures of benzoic acid, trityl chloride, trityl benzoate, and benzoyl peroxide iri benzene when diluted with 2 volumes of ethyl alcohol and titrated with standard aqueous base give a measure of the benzoic acid plus the trityl chloride. h sample treated similarly and analyzed for chloride ion by a Volhard titration measures the trityl chloride present. A third sample diluted with ethyl alcohol containing 1 or 2 nil. of standard 0.1 '%A hydrochloric acid is heated a t 54" for 20 to 30 minutes. Titration with sodium hydroxide gives the total analysis for benzoic acid, trityl chloride, and trityl benzoate. Vnder these conditions benzoyl peroxide yields very little acid. Analytical values for individual components are obtained by difference (56). Determination of the components of commercial dimethyl sulfate has been carried out as follows (69). A Lgram sample of the mixture in 20 ml. of ethyl alcohol or methanol is titrated directly wit,h standard 0.5 N sodium methoxide in methanol to bromocresol green. The total acidity resulting from methylsulfuric acid and sulfuric acid is obtained in this way. A 0.5- to 0.8-gram sample is treat,ed with 25 ml. of cold aqueous 0.5 N sodium hydroxide for 1.5 hours. Titration of the excess sodium hydroxide with acid t,o bromocresol green gives a measure of the methylsulfuric acid, the sulfuric acid, and the dimethyl sulfate which is hydrolyzed to methyl sulfuric acid. A 20- to 25-mg. sample with 1 gram of potassium iodide in 2 ml. of water is allowed to react for half an hour at room temperature and then for half an hour at 50" C. The methyl iodide formed is determined by the usual Zeisel technique. Only the dimethyl sulfate reacts under t,hese condit,ions. SILICOIV DERIVATIVES
Compounds of the type RSiIa, R2Si12, and RaSiI have been analyzed for iodine by the following procedure ( 5 , 6). A very thin-walled soft-glass capsule containing the sample is placed in the neck of a special round-bottomed flask containing double the theoretical amounts of sodium hydroxide and ethyl alcohol. The flask is stoppered and shaken until the capsule is shattered. In this way hydrogen iodide reacts with the base before ethyl iodide can be foimed, and the excess alkali can be determined by titration. SUGARS ASD DERIVATIVES
Sugar in fruit juices, liquors, brandies, etc., has been determined by a method involving the titration of a standard potassium ferricyanide solution with the sugar solution containing zinc sulfate. The end point is a complete decolorization of the solution because the potassium ferrocyanide formed during the oxidation of the sugar is precipitated as K2Zn3 [Fe(CK),]2. X 40-ml. sample of the standard 1% potassium ferricyanide solution is placed in a flask and 20 ml. of 2.5 ,V sodium hydroxide are added. The solution is brought to a boil and is then tit,rated with the sugar solution t o which zinc sulfate has been added.
tion should be used (18). Phenyl p-D-glucopyranosyl sulfones have been analyzed by quantitative cleavage with sodium periodate. A 0.17-gram sample in 5.00 ml. of 0.5 S sodium periodate is diluted t o 20 ml. with w a k r and allowed t o stand a t room temperature overnight. The reaction mixture is extracted continuously for 8 hours with ethyl acetate. The aqueous layer is transferred quantitatively and treated with excess sodium bicarbonate, diluted with 5 ml. of 0.05 ,Y sodium arsenite and 1 ml. of 2070 potassium iodide, and titrated with 0.05 11' iodine solution after 10 minutes. I n another determination the solution is not extracted with ethyl acetate nor neutralized, but is t.itrated with standard base to determine the amcunt of formic acid formed (15).
V O L U M E 2 4 , NO. 1, J A N U A R Y 1 9 5 2
113
#
Aldoses may be determined by a quantitat,ive application of the Kiliani reaction (38). At pH 8.5 and 39 O hydrocyanic acid adds quantitatively to aldoses. T h e resulting cyanohydrin is hydrolyzed and the ammonia formed is determined by titration. WATER
There have been several general discussions and reviews on the the use of the Karl Fischer reagent for the determination of water in organic compounds and mixtures (59, 66, 102). The preparation and standardization of the reagent have been discussed, and an alternative method of standardization which uses reagent grade methanol rat,her than anhydrous methanol has been suggested (122). Sodium tartrate dihydrate has also been recommended as a primary standard for the Karl Fischer reagent (106). Specifically the reagent has been used for the determination of water in preparations of xanthates and dithiocarbamates (85). Water formed as a product of the oxidation of methyl radicals has been determined by distillat,ion from the reaction vessel into a known amount of Karl Fischer reagent held in a liquid nitrogen trap. A blank is run on the reagent in exactly the same way (120). The amount of water formed during the Knoevenagel condensation has been follo~vedby the volume collected in a phase separator after distillation with benzene or toluene (119). T h e volumetric determination of water by xylene distillation has been modified by the suspension of the sample by means of a wire basket in the vapor space above the xylene. Several samples can be analyzed on one charge of xylene. The method is reported to be especially useful for routine analyses of foods (R7). R a t e r formed in the pyrolysis of phenyl phthalate has been determined by titration with toluene to an arbitrary cloud point (164). h 10-ml. sample of the reaction mixture (a Carbitol solution) is diluted with 10 ml. of Carbitol. Titration with toluene gives an arbitrary, but reproducible, cloud point. A blank is run on 20 nil. of Carbitol. An experimentally determined plot of amount o f water us. volume of toluene shows a linear relationship for 10ml. samples containing from 10 to 200 mg. of water. UNCLASSIFIED
iicidimetric, bromometric, and iodonietric methods for the determination of p-aminobenzoic acid have been described (86). T h e method of Jernistad and Oestby ( 6 4 ) for caffeine has been modified by substituting potassium bromate and potassium iodide in acid solution for the iodine solution ( 1 9 ) . T h e following procedure has been used for the determination of anethole. A 5-gram sample is mixed with 10 ml. of a 20% solution of mercuric acetate and refluxed gently for 4 to 5 hours. T h e mixture is cooled, treatedwith 20 ml. of 10% potassium chloride and 25 nil. of 0 . 1 T iodine, and then back-titrated n-ith sodium dithionites. Interference is caused by alcohols, ethylenes, and aldehydes, but methanol does not interfere ( 2 1 ) . . The carbon dioxide resulting from lead tetraacetate cleavage of sugars in acetic acid is separat,ed from most of the acetic acid by a water trap and then collected in a trap containing sodium hydroxide. Since some acetic acid is still present, barium chloride is added to the trap and the excess sodium hydroxide is titxated to a phenolphthalein end point. The barium carbonate precipitate is then titrated to a methyl orange end point ( 1 ) . T o measure the reaction of diazoketones with acetic acid
0
I1
RC-CHSz
0
+
CH3CO:H
I1
0
I1
RCCHZOCCH,
+
Kz
the nitrogen evolved is collected in a gas buret over water saturated with nitrogen ( 7 9 ) . Cationic surface active compounds (such as 2-heptadecylglyoxalidine) which are used as fungicides on fruits have been determined by titration with a standard solution of an anionic surface active agent (dioctyl sodium sulfosuccinate) in a chloro-
form-water mixture using methylene blue indicator (60). At the start of the titration the indicator is in the water layer, but as the equivalence point is rearhed it forms a chloroform-solublr complex s ith the anionic reagent. The color intensities of both layers match a t the end point. It is reported that when crude DDT is treated with 0 5 potassium hydroxide for 60 minutes a t 1 " to 5" only the pure ( p , p ' - isomer) D D T is hydrolyzed, and its percentage in the crude material may then be determined by back-titration (116). Chlorine in D D T can be eliminated in three stages, so that the amount of chlorine eliminated corresponds to either one, three, or five atoms of chlorine per molecule of D D T . To remove one atom of chlorine the sample is heated for 30 minutes a t 250 with a small amount of ferric oxide and a measured excess of standard sodium hydroxide solution while air is passed through the apparatus. Saponification of D D T with potassium hydroxide in ethylene glycol liberates three of the five atoms of chlorine in the D D T molecule. To prove the presence of D D T in the sample, p,p'-dichlorodiphenylacetic acid may be isolated from the saponification reaction. All of the five atoms of chlorine may be determined by any of the usual methods for total chlorine (157). Mixtures of the 01-, p-, y-, and &isomers of hexachlorocyclohexane may be analyzed by hydrolyzing the sample in four different mays (127). I n each procedure the various isomers are hydrolyzed to different extents and from the combined data the percentages of the various isomers may be calculated. When 0.4 gram of sample is hydrolyzed with 0.4 N sodium hydroxide in methanol for 20 minutes a t 100" all the isomers are converted to trichlorobenzene and labile chlorine is removed completely When the above procedure is carried out for 20 minutes a t 30" all but the 8- isomer react. K h e n treated with 0.0125 AVsodium hydroxide in methanol for 15 minutes 63y0 of the 01- and 6isomers and 35y0 of the y- isomer yield hydrogen chloride. I n repeating this latter treatment for 30 minutes instead of 15, 80% of the 01- and 6- isomers reacts and 51% of y- isomer reacts. T h e amount of hydrogen chloride liberated under each of the above conditions is determined by titration with 0.02 N mercuric sulfate in the presence of diphenylcarbazone. Phenolphthalein can be determined by oxidation with excess potassium bromate, followed by measurement of the excess,
A 0.1-gram sample is dissolved in 15 ml. of 0.1 N sodium hydroxide solution and treated with S to 10 ml. of 0.5 S potassium bromate, 5 ml. of 10% potassium bromide, and, with shaking, 25 ml. of an acid mixture (20 ml. of 80% acetic acid and 5 ml. of concentrated hydrochloric acid). The shaking is continued for 1 minute and then 1 gram of potassium iodide is added and the liberated iodine is titrated with 0.1 S sodium thiosulfate, Each milliliter of 0.1 S potassium bromide is equivalent to 0.003977 gram of phenolphthalein. A blank should be run (118).
Bis(diethylthiocarbamy1)disulfide has been determined in the following way. T h e sample (0.4 to 0.5 gram) is dissolved in carbon tetrachloride and to 3 to 4 ml. of this solution are added 5 ml. of carbon tetrachloride, 10 ml. of ivater, and 10 ml. of concentrated hydrochloric acid. T h e mixture is titrated n-ith 0.1 N bromate-bromide solution. A blank determination is necessary. By substituting chloroform for carbon tetrachloride the method can also be used for bis(dimethylthiocarbamy1)disulfide (36) The ion exchange resins, Amberlite IR-120 (H form) and IR4B (OH form), are used to remove all electrolytes of loir molecular weight from aqueous solutions of high moleciilar R-eight pectins and pectates. By suitable analyses and calculations carboxyl, ester, methoxyl, and acetyl groups may he determined on the resultant solutions ( 7 ) . Some previously described methods (48,87) have been used recently for starch acetates, propionates, butyrates, caproates, palmitates, and benzoates ( 1 6 0 ) . The following procedure has been used for the determination of sodium alginate ( 4 4 )
ANALYTICAL CHEMISTRY
114 Twent,y-five millilit,ers of a solution containing 3 to 15 nig. of sodium alginate are mixed with 40 ml. of 0.01 A’ ceric sulfate, 100 mg. of silver sulfate, and 5 grams 3 f potassium sulfate. The mixture is boiled gently for 2 minutes, diluted to 100 ml. with cold water, and filtered t,hrough a dry filter. A 50-ml. aliquot of the filtrate is titrated with a standard ferrous ion solution to a ferroin end point. One milliliter of 0.1 S solution is equivalent to 1.2 mg. of sodium alginate. Terminal bromodinitromethyl groups, -CBr (SO,)g,can be determined by a halogen analysis. Treatment of compounds containing these groups ivith an alkaline reagent was unsatisfactory because the color of t,he resultant solutions obscured the end point for the subsequent silver nitrate titration. However, these groups can be determined satisfactorily by treating the sample with potassium iodide and titrating the iodine liberated with standard thiosulfate ( 7 7 ) . I n some kinetics studies alkyl sulfuric acid and unchanged sulfuric acid were determined by titration with standard base (29). The concentration of acetate ion in acetic acid has been followed by titration n-ith a standard solution of p-toluenesulfonic acid in glacial acetic acid, or, better, by adding a slight excess of the standard acid solution and back-titrating with sodium acetate in acetic acid (163). A rapid method for determining aconitic acid in molasses, solutions from fermentations, and crude aconitates utilizes oxidation with standard potassium permanganate solution (81). The titration is carried out in a slight excess of sulfuric acid and at boiling temperature. The amount of oxygen consumed depcnds upon the concentration of the permanganate used, and not upon the concentration of aconitic acid. The amount varies from 15 oxygen atoms per molecule of aconitic arid with 0.05 to 0.1 S permanganate to the theoretical 9 oxygen atoms per molecule of aconitic acid with 1 11’ permanganate. As carried out the procedure is empirical, and the permanganate solution is standardized against a pure sample of aconitic acid. The results compare favorably with those obtained by the more complex decarboxylation procedure (123). The permanganate titration procedure can also be used for itaconic acid, but is not satisfactory when the samples are impure. Iodometric equivalent 4-eights of diary1 selenoxide-mercuric halide complexes have been obtained by dissolving a sample in warm methanol, adding an excess of acidified potassium iodide solution, and titrating the released triiodide ion with standard thiosulfate ( 5 3 ) . Betaine may be precipitated quantitatively as the reineckate and washed free of inorganic acid with ether. The precipitate is then dissolved in aqueous acetone and the reineckate ion is removed by addition of excess silver nitrate. The resulting solution of betaine nitrate is then titrated with sodium hydroxide, using methyl red indicator (153). The arid number of oils and resins has been determined in aqueous niediuni by a process which involves using an emulsified sample (105). A modification of previously described procedures (90, 81, 95) using mercuric acetate for the determination of unsaturation has been applied to the determination of rotenone ( 6 2 ) .
(8) Assoc. Offic. 4gr. Chemists, “Official and Tentative Methods of Analysis,” pp. 295-6, 1945. (9) Attwood, C. IT., Ford, I. A. M.,Hoyle, E. R., and Parkes, D. IT.. J . SOC.Chem. Ind.. 69. 181 (1950). (10) Baltzly, R., Berger, J. M . , and Rothstein, A. A., J . Am. Cliem. Soc., 72, 4149 (1950). (11) Besson, S., and Petot, M,, Bull. soc. sci. S a n c y , 8 , 36-9 (194950). (12) Blom, J., and Schwarz, B., Acta Chem. Scand., 3, 1439 (1949). (13) Blomquist, A. T., and Buselli, A. J..J . Am. Chem. Soc., 73, 3883-8 (1951). (14) Blomquist, A. T., and Ferris, -1.F..Ibid., 73, 3408-11 (1951). (15) Bonner, W. A., and Drisko, R. TI-., Ibid., 73, 3699-701 (1951). (16) Brissaud, L., and Perriot, G., Chirn. anal.. 32, 241-5 (1950). (17) Bryant, W..M. D., and Smith, D. AI., J . Am. Chem. Soc., 57, 57 (1935). (18) Bukharov, P. S., and Podlubnaya, E. T., Zhur. Anal. K h i m . , 5 , 300 (1950). (19) Carlassary, hl., Bull. chim.farm., 90, 4-13 (1951). (20) Cass, W.E., J . Am. Chem. Soc., 72, 4915 (1950). (21) Chauveau. J.,Bull. soc. chim. France, 1949, 614-15. (22) Clark, E. P., “Semimicro Quantitative Organic Analysis.” p. 73, Sew York, .4cadernic Press, 1943. (23) Cohen. S. G.. Groszos. S.J.. and Saarrow. D. B.. J . A m . Chem. Soc., 72, 3947 (1950). (24) Cohen, S. G , and Haas, H C., Ibid , 72, 3954-8 (1950). (25) Cristol, S. J , Overhults, IT- C , and Meek, J. S , I b z d , 73, 813-5 (1951). (26) Cristol, S. J., Ragsdale, J. IT., and RIeek, J. S., Ibid., 73, 810-13 (1951). 1271 Danes, V., and Rund, B., Chem. Listy, 41, 133 (1947). 1 Deinum, H. IT., and Schouten, A , , Anal. Chim. Acta, 4 , 286 (1950). Deno, N. C., and Newman, RI. S.,J . A m . Chem. Soc., 72, 3852-6 (1950). Dirscherl, A,, and Kagner, H., Mikrochemie Der. Mikrochzm. Acta, 36/37, 628-33 (1951). Dolezal, J., and Simon, V., Chem. Listy, 44, 169-77 (1950). Dorfman, L. >I., and Salsbury, 2. W.,J . A m . Chem. Soc., 73, 255-7 (1951). Dupuy, P., Compt. rend., 232, 836-8 (1951). Eastham, A. ill:, and Latremouille, G. -1.. Can. J . Research. 28B, 264-7 (1950). Eschinazi, H. E., and Bergmann, E. D., J . A m . Chem. Soc., 72, 5651-4 (1950). Ferreira, P. C., Arquin. biol., 34, 105 (1950). Fortunato, -1.D., and Hourquebie, H., Rep. Argenlina M i n i sterio ind. y com. nacion, Direc. gen. ind. m a n u f . Inst. tecnol. Ser. A , S o . 4 , 3-19 (1950). Framoton. V. L.. Folev. L. P.. Smith. L. L.. and Malone. J. G.. ANAL. CHEM.,23, l”244 (1951). Francls, A. W., I n d . Eng. Chem., 18, 821-2 (1926) Freeman, S . E , and McCullen, B. V., J . Assoc. Ofic. Agr. Chemists, 31, 550-8 (1948). Friedrich, A,, Mikrochemie, 23, 129-43 (1937). Fritz, J. S.,and Lisicki, N. >I., ANAL CHEM.,23, 589 (1951). Furukawa, T., and Sagase, O., J . Pharm. SOC. J a p a n , 70, 590-1 (1950). Gaedeke, A , . Z . anal. Chem., 131, 428 (1950). Gasser, F., Osterr. Chem.-Ztg., 51, 206-7 (1950). Gatterer, A., Mikrochemie ver. Mikrochim. S c t a , 36/37, 641-7
(lqjl). Gautier, J. A , . Proc. X I t h Intern. Cong. Pure and Applied Chem. (London). 2. 95-7 (1947).
Genurig, L. B..and hlallatt, R. ‘C., IND. ENG.CHEM.,~ ~ B A L . ED., 13, 369 (1941). George, J., Mark, H., and Wechsler, H., J . Am. Chem. Soc., 72, 3896-901 (1950).
George, J., Wechsler. H., and Mark, H., Ibid., 72, 3891-6 (1950).
Gilrnan, H., Wilkinson, P. D., Fishel, IT. P.. and hfeyers, C. H., Ibid., 45, 150-8 (1923).
LITERATURE CITED (1) Abraham, S.,J . Am. Chem. SOC.,72, 405@3 (1950). (2) igren, A . , Svensk Farm. Tid., 55, 229-38 (1951). (3) Alexander, E. R., and Dittmer, D. C., J . A m . Chem. Soc., 73, 1665-8 (1951). (,4) Aluise, V. A , , Alber, H. K., Conway, H. S., Harris, C. C., Jones, IT. H., and Smith, W. H., ASAL. CHEM.,23, 530’ (1951). (5) Anderson, H. H., J . A m . Chem. Soc., 73, 2351-2 (1951). (6) Anderson, H. H., Seaton, D. L., and Rudnicki, R. P. T., Ibid., 73, 2144 (1951). (7) .4nyas-Weisz, L., Solms, J., and Deuel, H., M i t t . Lebensm. Hyg., 42, 91-106 (1951).
Glichitch, L. S.,Bull. soc. chim., 33, 1284-96 (1923). Gould, E. S., and McCullough, J. D., J . -4m. Chem.
S o c . , 73, 3196-7 (1951). Hahn, F. L., A n a l . Chim. Acta, 4 , 577-9 (1950). Hammond, G. S., Rudesill, J. T., and >Iodic, F. J., J . d m . Chem. Soc., 73, 3929-31 (1951). Hammond, G. S., and Sofer, L. S., Ibid., 72, 4711-15 (1950). Haslam, J., and Clasper, If., Analyst. 76, 33-40 (1951). Hayazu, R., J . P h a r m . Soc. J a p a n , 70, 741-2 (1950). Hellberg, H., Farm. Revy, 49, 287 (1950). Hillenbrand, E. F., Sutherland, W.IT., and Hogsett. .J X.. ANAL.CHEM.,23, 626 (1951). Hirai. >I., and Hayatsu. R.. J . Pharna. SOC.J a p a n . 70, K O - 1 (1950).
V O L U M E 24, NO. 1, J A N U A R Y 1 9 5 2 (62) Hornstein, I., ANAL. CHEM.,23, 1329 (1951). (63) Jackson, E. L., “Organic Reactions,” 1-01. 11, p. 361 (1944). (64) Jermstad, A . , and Oestby, O., Dansk Tids. Farm., 7, 117-22 (1933). (65) Jones, A. C., A n a l y s t , 76, 5-12 (1951). (66) Jones, J. H., J . Assoc. Oflc. Agr. C h m i s f s , 33, 381-4 (1950). (67) Jones, J. H., and Gordon, X . , Ibid., 32, 680-4 (1949). and Palkin, S., ISD. ENG.CHEM., 168) Joshel, L. RI., Hall, 9. -4., ANAL.ED.,13,447 (1941). (69) Jurecek, R I . , Chem. L i s t y , 44, 134-6 (1950). (70) Kahane, E., Bull. soc. chim. France, 1951, 92-4. (71) Kainz, G., Mikrochemis w r . Mikrochim. Acta, 38, 124 (1951). (72) Kaufmann, H. P., Fette u.Seifen, 47, 4-5 (1940). (73) Kaufmann, H. P.. 2. Unteisitch. Lebensm., 51, 3-14 (1926). (74) Kaufmann, H. P., and Baltes, J.,F e t f e u . S e i f e n , 43, 93-7 (1936).
( 7 5 ) Kemp, A. R., and Mueller, G. S..IND.ENG.CHEM.,ANAL.ED., 6,52 (1934).
(76) Kirsten, IT., Mikrochemie wr. Mikrochini. A c t a , 35, 174-5 (1950). 177) Blager, K., ANAL.CHEM.,23, 534 (1951). (78) Klaus, G., and Reynolds, I T . B., J . A m . Chem. Soc., 72, 5621-6 (1950). (79) Lane, J. F., and Feller, R. L., Ibid., 73, 4230-4 (1951). ( 8 0 ) Lane, J. F., and Spialter. L., Ibid., 73, 4408-10 (1951). (81) Lauer, K., and Makar, S.hI., ANAL.CHEM.,23, 587 (1951). (82) Lenaers, G., J . ?,harm. Bely., N.S., 5, 224 (1950). (83) Linch, A. L., A K . ~ , .CHEM.,23, 293-6 (1951). 184) Lubatti, 0. F., J . SOC.Chrnz. I n d . , 54, 424T (1935). (85) McKcnna. F. E., Priest, H. F., and Staple, E., Katl. Kuclear Ynergy Sr.,Div. VIII, 1 , Anal. Chem. Manhattan Project 226-48 (1950). (8(i) Mapder H., - 4 ~ 0 t hZtg., . 27, 748-7 (1912). ( 8 7 ) Rfalnl, C,. J., Genung,’J. B., Williams, R. F., Jr., and Pile, 11.A , , ISD. ESG. CHEM., A s a ~ ED., . 16, 501 (1944). ( 5 8 ) Maltby, J G., and Primavesi, G. R., A n a l y s t . 74, 498 (1949). (89) LIarkunns, P. C., and Riddick. J. .4.,- 4 s ~CHEM., ~. 23, 337-9 (1951 t‘ (90) AIarquai,dt, R . P., and Lucc, E. S . , Ibid.. 20, 751-3 (1948). (91) I h i d . , 21, 1194 (1949). (92) Marques, 1 2 . C , and Alliato, G., Tec. y econ., 1949, KO.2, 55-8. (93) RIarszak, I., and Roulkes, AI., Bull. soc. chim. France, 1950, 364-5. (94) Martin, F., Mikrochemie rer. Mikrochim. Acta, 36/37, 653 (1951). (95) Nartin, R. W., SNAL. CHEM.,21, 921 (1949). (96) Marzadro, RI., Mikrochemie m i . Mikrochim. Acta, 36/37, 671-5 11951). (97) Marzadro, hf., R e n d . i s t . super. sanitb, 13, 702-10 (1950). (98) Mead, J. F., and Howton, D. R.. ANAL.C H m f . , 22, 1204 (1950). (99) Nikusch, J. D., Angcw. Chem., 62, 475 (1950). (100) Miller, S.A,, and Pearman, F. H., A n a l y s t , 75, 492 (1950). (101) Miller, S. A, and Williams, ?i. E., Ibid., 76, 224-9 (1951). (102) Mitchell, J., Jr., ANAL.& E l f . , 23, 1069 (1951). (103) hloelants, L., Mendelel. Vlaam. Chem. Ver., 12, 120 (1950). (104) Mueller, K. H., and Walters. TI-. D., J . A m . Chem. Soc., 73, 1458--61 (1951). (105) Sarsimhan, G., and Saletore. S. -4.,ANAL.CHEM.,23, 1315 (1951). . 23, (106) Seuss, J. B., O’Brien, hI. G., and Frediani, H. 9.Ibid.. 1332 (1951). (107) Nichols, P. L., Jr., Herb, S. F., and Riemenschneider, R. IT., J . Am. Chem. S O L , 73, 247-52 (1951). (108) Koll, A , , and Belz, W., Papier-Fabr., 29, Tech.-wiss Teil, 33-4 (193 1). Ibid., 28, Tech.-wiss Teil, 565-8 (109) Soli, A , , Bolz, F., and Belz, W., (1930). (110) Ogata, Y . , Okano, M.,and Sugawara, RI., J . Am. Chem. Soc.. 73,1715 (1951). (111) Pearson, R. G., and RIayerle. E. A , . Ibid., 73, 926-30 (1951). (112) Pearson, R. G., and Sandy, A. C., Ibid., 73, 931-4 (1951). (113) Perrot, R., and Barghon, A . , Proc. X I t h Intern. Congr. Pure w i d Applied Chem. ( L o n d o n ) , 2 , 247-51 (1947). (114) Pippen, E. L.. RIcCreedy, R. &I., and Owens, H. S.,Ax.4~. CHEXf., 22, 1457 (1950). (115) Ploquin, J., Compt. rend., 231, 1066-8 (1950); 232, 164-5 (1951). (116) Pluchon, J.. and Pille, G., M e d . trop., 9 , 532 (1949). (117) Foethke, IT., P h a r m . Zentrolhalle, 86, 357 (1947). (118) Popov, S. F., M e d . P r o m . S.S.S.R., 1949, KO.6, 25. (119) Pratt, E. F.. and Verble, E., J . A m . Chem. Soc., 72, 4638-41 (1950). (120) Raley, J. H., Porter, L. M., Rust, F. F., and Vaughan, W.E., I b i d . , 73, 15-17 (1951). (121) Rapaport, F. M., Z a m d s k a y a Lab.. 16, 560 (1950).
.
115 (122) Ricciuti, C., and !I-illits, C. O., .I. Assoc. Oflc.A y r . Chemists, 33. 469-73 11950). (123) Roberts, E. J., and Amber, J. -4.. IND. ESG. CHEM.,d x . 4 ~ED.. . 17, 637 (1945). (124) Rodigliero, G., A n n . chzm. applicata, 38, 632-43 (1948). (125) R o e , E . T., and Swern. D., Ak.4~.CHEI~., 22, 1160 (1950). (126) Ross, S. D., and Fineman, R f . A , , J . Am. Chem. Soc., 73, 217681 (1951). (127) Roth, H., Z . anal. Chem., 131, 347 (1950). (128) Sabetay, S.,Intern. Perfu,mer. 1 , KO,2, 11-13 (1951). avary, P., B u l l . soc. chim. France, 1950, 624. chiessler, R. TI-.,Speck, R. hI., and Dixon, J. A , , J . . 4 n ~ Chem. Soc., 73, 3524-6 (1951). (131) Schnell, H., Makromol. Chem., 2 , 172-5 (1948). (132) Schoniger, IT., Z . anal. Chem., 133, 4-7 (1951). (133) Schoniger, W.,and Lieb. H., Mikrochemie w r . Mikrochim. Acta. 38, 165-7 (1951). (131) Schwab, G. AI., and Schwab-bgallidis, E., J . Am. Chem. Soc., 73, 803-9 (1951). (135) Seaman, TT., and .Illen, E., ASAL. CHEM.,23, 592 (1951). (136) Shaeffer, W.E., and Balling, W.J., Ibid., 23, 1126 (1951). (137) Shafer, H., and \Tilde, E., 2. unal. Chern., 130, 396-401 (1950). (138) Sharp, L. K., A n a l y s t , 76, 215 (1951). (139) Shorina, 52. D., Zacodsknya Lab., 13, 1180-1 (1947); Chem. Zentr. (Russian Zone E d . ) , 1948, I, 495. (140) Siggia, S., Hanna, J. G., and Kervenski, I., ANAL.CHEM.,22, 1295 (1950). (141) Siggia, S., and Kervenski, I. R., Ibid., 23, 117 (1951). (142) Stewart, 1’. E., J . Assoc. O f i c . A g r . Chemists, 33, 214--18 (1950). (143) Swain, C. G., Stockmayer, W. H.. and Clarke, J. T., J . A m . Chem. Soc., 72, 5426-34 (1950). (144) Szeberenyi, P., Magyar KQm. Folydirat, 56, 64-6 (1950). 1145) Takagi, S., Suzuki, T., and Imaedo. K., J . P h a r m . Soc. Japan, 71, 82-4 (1951). (116) Taylor, M.D., J . Am. Chem. Soc., 73, 315-17 (1951). ~I
(147) Terent’ev, A. P., and Kireeva, A . I., Isoest. A k a d . S a u k S . S S.R. Otdel. Khim. S a u k , 1951, 172-8. (148) Tomieek, O., and Doledal, J., Chem. L i s t y , 43, 193 (1949). (149) Unterzaucher, J., Ber., 73B, 391-4 (1940). (1.50) rnterzaucher, J., Mikrochemie rer. Mikrochim. Acta, 36/37, 706-26 (1951). (151) VanEtten, C. H., and Wiele. AI. B., ‘;~YAL. CHEM.,23, 1338 (1951). (152) Vassilev, G. A., Bull. soc. chim. France, 1950, 750. (153) ]Talker, H. G., Jr., and Erlandsen. R., b s a ~ CHEM., . 23, 1309 (1951). (154) Walling, C..and McElhill. E. -4., J . Am. Cheni. Soc.. 73, 292731 (1951). (155) Watanabe, T., and Ishinose, T., J . P h a r m . Soc. J n p a n , 63, 36 (1943). (156) I b i d . , p. 691. (157) Weber, E., 2. anal. Chem., 132, 26-33 (1951). (158) Willard, H. H., and Horton, C. A,, ANAL. CHmr., 22, 1190-4 (1950). (159) Wilson. G. E.. J . I n s t . Petroleum 36. 25-42 (1950). (160) SF’olff, J . A,, bids, D. IT., and Hilbert, G.E.. J: Am. Chem. SOC.,73, 348-9 (1951). (161) Wurzschmitt, B., Chem.-Ztg., 74, 356 (1950). (162) Wurzschmitt, B., Mikrochumie re?. Mikrochim. A c t a , 36/37, 614-27 (1951). (163) Young, I\-.G., Winstein, S., and Goering, H. L., J . Am. Chem. SOC., 73, 1958-63 (1951). (164) Zelinski, R . P., and .-lndersen, H. &I.,Ibid., 73, 4405 (1951). (165) Zimmermann, JT., Mikrocheinie per. Mikrochiin. d c t a , 31, 1536 (1943).
RECEIVED October 30, 1951
SKINNER & SHERMAN. INC.
