V O L U M E 23, NO. 1, J A N U A R Y 1 9 5 1
115
(433) Thomas, M. D., U. S. Patent 2,462,293 (1949). (434) Thomas. M. D.. and Ivie. J. 0.. “ADDlication of Electrolvtic
Conductivity of Gas Analysis,” -ibstracts, 97th Meetlng, Electrochemical Society, 1950. (435) Thorp, R. H., Electronic Eng.. 17, 671 (1945); Science A b stracts, A50, No. 590, 58 (1947). (436) Tieghi, M., Ital. Patent 427,880 (1947). (437) T i m e , LV, No. 4, 54 (1950). (438) Tracerlab, Inc., Catalog B; Instrumentation, 4, No. 2, 18 (1949); Tracerlog, Nos. 15, 16, 2 0 , 2 1 , 2 4 , 2 5 (1949 and 1950). (439) Trigg, TV. M., Chem. EwJ., 57, No. 5, I56 (1950). (440) Trimount Instrument Co., Data Sheet 150. (441) Tunnicliff, D. D., - 4 x . k ~ .C m x . 20, 962 (1948). (442) Turnbull, J. C., J . A m . Ceram. Soc., 33, 54 (1950). (443) Untersaucher, J., Chem. Ing. Tech., 22, 39 (1950). (444) Ibid., p. 128. (445) Urosovskaya, L. G., and Frank-Kamenetskii, D. A , , Zacodskaya Lab., 14, 12 (1048). (446) Vacca, C., Rin. med. aeronaut., 12, 400 (1949). (447) Vacuum-Electronic Engineering Co., B u l l . LD-6. (448) Vance, E. R., J . Metals, 1, S o . 10, 28 (1949). (449) Verdery, R. B., Jr., Chemist-Analyst, 38, 68 (1949). (450) Victory Engineering Corp., advertising literature. (451) Vinogradov, A. F., and Karadov, V. A., Zavodskaya Lab., 14, 40 (1948). (452) Tisman, J., Fuel, 29, S o . 5, 101 (1950). (453) Voland & Sons, Inc., advertising literature. (454) \-old, M. J., ANAL. CHEM., 21, 683 (1949). (455) Von Brand, E. K., Mech. Eng., 72, 479 (1950). (456) Vuorelainen, O., TekriiZlinen Aikakauslehti, 40, 39 (1950). (457) Vylomov, V. S.,Zaaodskaya L a b . , 14, 1134 (1948). (458) Wallace, C. F., U. S . Patents 2,360,378 (19441, 2,482,078 (1949). (459) Wallace & Tiernan, PubZ. TP-59-C. (460) Watson, C. C., U. S.Patent 2,456,163 (1948).
\teerile. E., Gas J . , 259, 782 (1949); Gas World, 130, 1200 (1940); Inst. Gas Engrs., Copyright P u b l . 353, 36 (1949). ( 4 6 ) \reaver, E. R., and Riley, R., ANAL.CAEM.,20, 216 (1948); (461)
(463) (464) (465) (466)
J . Research Y a t l . B u r . Standards, 40, 169 (1948); Refrig. Eng., 55, 266 (1948). Weiss, O., U. S. Patent 2,416,808 (1947). Weissberger, 8., “Physical Methods of Organic Chemistry,” S e w York, Interscience Publishers, 1949. IVeisz, P. B., U. S. Patent 2,485,424 (1949). Westinghouse Research Laboratories, A m i n c o Laboratory N e w s , 5, No. 6 (1948).
(467) Weston Electrical Instrument Corp., advertising literature. (468) Wheelco Instrument Co., B u l l . C2-1 (1947). (469) Wherry, T. C., and Crawford, F. W., Oil Gas J., 48, 272 (1950); Phillips Petroleum Co., B u l l . 280 (1950). (470) White, J. U., Liston, M. D., and Simard, R. G., ANAL.CHEM., 21, 1156 (1949). (471) TTiener, N., “Cybernetics,” Neb York, John Wiley & Sons, 1948. (472) Willard, H. H., “Instrumental Methods of Analysis,” New York, D. Van Kostrand Co., 1948. (473) Williams, A. E., Eng. and Boiler House Rev., 63, 254 (1948). (474) Williams, P. S.,A n a l y s t , 74,400 (1949). (475) Wilson & Co., advertising literature. (476) Winkler, L. T., U. S.Patent 2,387,550 (1945). (477) Wise, W.S., Chemistry and I n d u s t r y , 1948, 37. (478) Yardley, J. T., Chem. Products, 11, 233 (1948). (479) Yunker, W.S., Paper Mill N e w s , 70, No. 43, 34 (1947). (480) Zaikowsky, W. hl., U. S. Patent 2,505,535 (1950). (481) Zaukelies, D., and Frost, A. A., ANAL.CHEM., 21,743 (1949). (482) Zellweger, A,-G. Apparate- und Maschinenfabriken Uster, Sn-iss Patent 245,721 (1947). (483) Zemany, P. D., Winslow, E. H., Poellmits, G. S.,and Liebhafsky, H. A., ANAL.CHEM.,21, 493 (1949). RECEIVEDOctober 16, 1950.
Determination of Superoxide Oxygen EDGAR SEYB, JR.,
.&VD
JACOB KLEINBERG
University of Kansas, Lawrence. k i n .
A problem in progress in the authors’ laboratory required a good analytical method for differentiating between superoxide and peroxide oxygen in solid materials. It was found that superoxide oxygen in such materials can be determined with reasonable accuracy by treatment of the solid with a mixture of glacial acetic acid and diethyl phthalate. No secondary decomposition of peroxide occurs. The method discovered should be of considerable value to workers in the superoxide field. I t has already proved valuable in this laboratory in the solution of a problem involving synthesis of mixed superoxides-peroxides.
T
HE development in recent years of potassium superoxide, K 0 2 , as a chemical for air purification-Le., the absorption
of cwbon dioxide and water vapor from the atmosphere with the concomitant liberation of oxygen-has greatly stimulated interest in the theoretical and practical aspects of superoxide chemistry. However, exact experimental work in many phases of research on superoxides has been hampered by the lack of a suitable method for the determination of superoxide oxygen. Holt and Bms (2) first reported that potassium superoxide reacts with water vapor in accordance with the equation
2K02
+ aq. = K202.aq. +
0 2
The same reaction presumably takes place with liquid water a t 0 ” C. (4). I n theory, this reaction offers a rapid method for determining superoxide oxygen; in practice, however, it is impossible to avoid secondary decomposition of the peroxide formed and results are erratic and consistently high. (Decomposition of the peroxide has been attributed t o local heating and the catalytic effect of hydroxide ion formed in the reaction.) It has been demonstrated recently (6) that sodium superoxide
(a paramagnetic substance), when in admixture with sodium peroxide, may he determined with reasonable accuracy by a magnetic method. The magnetic method, however, is considerably limited in scope. It is of little value if more than one diamagnetic impurity is present, or if the sample contains other paramagnetic substances. Preliminary experiments (6) in the authors’ laboratory on the decomposition of sodium peroxide-sodium superoxide mixtures by means of solutions of glacial acetic acid in carbon tetrachloride indicated that the oxygen evolved in such decomposition provided a semiquantitative measure of superoxide content. It was difficult, however, t o determine the exact point a t which release of Superoxide oxygen was complete. The present paper describes the use of a glacial acetic acid-diethyl phthalate solution for the determination of superoxide oxygen. The results of experiments indicate that this solution quantitatively converts superoxides to oxygen and hydrogen peroxide. There is little, if any, release of oxygen by the secondary decomposition of the hydrogen peroxide formed. Thus, the procedure utilized would appear to he applicable to any mixture containing superoxide ion.
ANALYTICAL CHEMISTRY
116 The method of analysis described in this communication is not applicable to materials containing the OS-(ozonide) ion, which has been recently characterized (8,7). However, the methods by which superoxides are prepared are considerably different from those utilized for the preparation of ozonides, and there i s little likelihood of finding ozonide impurities in materials containing superoxide ion. PROCEDURE
The system employed in the analysis of superoxides (Figure 1 ) consisted essentially of a reaction cell, D-E, of about 100-ml. capacity, connected to a water-jacketed gas buret, G , by means of capillary tubing. The reaction cell was composed of the cell head, D joined to the cell body, E , by a ground-glass joint. The various solutions utilized to deconipose the superoxide samples were added through the dropping funnel, B , which was connected to the cell by meana of a three-way stopcock, C.
3
RESULTS
The proposed method for the determination of superoxide oxygen was tested on both samples of relatively high purity potassium superoxide and mixtures of sodium superoxide and sodium peroxide. The samples of potassium superoxide gave upon total catalytic decomposition values in the neighborhood of 230 ml. of available oxygen (S.T.P.) per gram of material. Two thirds of this quantity should be liberated in the conversion of superoxide ion to hydrogen peroxide by decomposition with acetic acid-diethyl phthalate mixtures. This is illustrated by the stoichiometry of the following equations:
2K02
+ 2HCzH30z = 2KCzHsOz + HzOz + 02 HzOz = Hz0 + '/zOz
The experimental values obtained for the release of superoxide oxygen are shown in Table I. I t is evident that the agreement with the theoretical value is excellent, and the conclusion must be reached that there is little decomposition of the peroxide which is formed from the superoxide. An excellent test of the method was offered by the analysis of sodium superoxidesodium peroxide mixtures. The mixtures were prepared by treatment of sodium peroxide with oxygen at high pressures and temperatures, as described in a previous communication (6), and were so chosen as to give a fairly wide range of superoxide content. They were analyzed for superoxide by two independent methods. First a total catalytic decomposition was carried out. From the quantity of oxygen released the theoretical superoxide content was obtained by the following equation :
T
9
Figure 1. Diagram of Apparatus
'
1 M in hydrochloric acid and 3 M in ferric chloride, or the first step in the decomposition-Le., with acetic acid-diethyl phthalate solution-was followed by the catalytic treatment. The latter manner of decomposition permits determination of both superoxide and peroxide ions on the same sample in any mixture containing these substances. The first method for determining total oxygen proved to be a little more precise, and was utilized when sufficient material was available to permit an independent determination of superoxide content on another sample.
A weighed oxide sample (preferably 0.1 to 0.2 gram) was transferred to the cell body in a dry box which contained anhydrous magnesium perchlorate; the cell body was stoppered, removed from the dry box, and rapidly connected to the cell head. The system was then swept out with oxygen, which was dried by passage through anhydrous magnesium perchlorate in A . The reaction cell was thermostated a t 0" by means of an ice-water bath and buret readings were taken until equilibrium had been established. Exactly 5 ml. of diethyl phthalate (Eastman) were introduced into the cell through funnel B , followed by the slow addition (10 to 15 minutes) of exactly 10 ml. of a mixture of glacial acetic acid and diethyl phthalate (8 volumes to 2 volumes, respectively). Throughout the addition of the acetic acid solution the contents of the cell were stirred by means of the magnetic stirrer shown in Figure 1; this permitted gradual contact between the oxide sample and the acetic acid, and, therefore, a slow release of superoxide oxygen. Buret readings were taken a t &minute intervals until a constant value had been obtained. The volume of gas liberated, when corrected for the addition of the decomposing solutions, gives a measure of oxygen evolved in the conversion of superoxide to peroxide. The sample, when decomposed as described above, no longer contained the yellow color characteristic of superoxides. The total quantity of oxygen available in the superoxide sample-Le., that amount resulting from reaction of both the superoxide ion and the peroxide obtained from the former's decomposition-was determined in one of two ways. The sample was either completely decomposed catalytically with a solution of
Cc. of oxygen evolvedlgram of sample 305 - 144
- 144 X l o o = %
NaO?
where the numerator represents cubic centimeters of oxygen evolved per gram beyond that required for pure sodium peroxide and the denominator the difference in cubic centimeters of oxygen evolved per gram between pure sodium superoxide and sodium peroxide. Then the acetic acid-diethyl phthalate decomposition was carried out, yielding a second value for superoxide content. This was calculated from the equation: Cc. of oxygen evolved per gram of sample on acetic aciddiethy1 phthalate treatment X 100 = 2/3 x 305
Table I.
% ' Na02
Liberation of Superoxide Oxygen by Potassium Superoxidea
Total Oxygen Calcd. SuperObsd. Superoxide Oxygen Liberated oxide Oxygen Wt. of Sample cc./g. cc./o. Gram Ce./g.b 151 154 0.1672 227 0,1492 227 151 155 0,0901 233 155 155 0,1035 228 152 151 0.1361 233 155 155 0.1104 230 153 152 0.1031 233 155 159 Su plied by Naval Research Laboratory, Washington, D , , C . b Varues in this column obtained by two-step decomposition of sample, first step involving liberation of superoxide oxygen, and second the catalytir decomposition of peroxide left in solution.
117
V O L U M E 2 3 , NO. 1, J A N U A R Y 1 9 5 1 Tahle 11. W e i g h t of Sample Gtarn
Determination of Superoxide Oxygen in Sodium Superoxide-Sodium Peroxide Mixtures Oxygen Liberated on Total Decomposition cc./g.
(S. T P.)
Siinerowde Calcd. 6%
Superoxide Ovygena Liberated
cc :g.
Superoxide Obsd.
%
0 8956 0 0603 0.3121 0.2204 0,0983 0,1556
170
16.1
30.9 30.7
15.2 15.1
171
18.G
37.4 35.9
18.4 17.7
191
28 .i
36.0 58.5
27.6 28.8
0.1617 0.1647
234
26 0
111 113
0,0691
273
80.2
159 161
5G.0 55.8 78.1 79.4
206
94.3
188 192
92.6 94.5
0,0397
0 . 12,53 0.1178
" Piire uhite sodium ueroxide, supplied by .\line Safety Appliances Co., Pittsburgh, Pa., liberated no oxygen when treated with acetic acid-dlethyl phthalate solution. Game material treated with water a t O n yielded 7.7 and 12.0 cc. of oxygen (S.T.P.) per gram i n two experiinents.
ivlit~w the denominatcr is tlir t1icoretir;d quaiit,ity of oxygt'il avnilablc: per gram of pure sodium superoxide upon conversion to iwroside. The data of T:ihle I1 s h o ~t h a t i n the rase of sodium superoxide-sodium peroxide mixtures 1 1 1 t h vitlurs obtained for superoxide roiltent agrer rc:tsonably n.c.11 n-ith the theoretical, when one considers the extreme viisiit iyit). of superoxides to moisture. It is j)articularl,v striking that pure sodium peroxide liberates no oxygen upon treatment with acetic acid-diethyl phthalate mist,ures. This again emphasizes the fact that there is little, if any,
release of oxygen by the secondary decomposition of hydrogen peroxide in solution, and demonstrates t'hat the method employed is applicable to mixtures containing superoxide ion. Samples of sodium superoxide which on total decomposition with ferric chloride-hydrochloric acid catalyst solution released 296 cc. of oxygen (S.T.P.) per gram, liberated 203 and 245 re. of oxygen (S.T.P.) per gram Lvhen treated with water a t 0". Since theoretical release of superoxide oxygen for these samples is 192 cc. (S.T.P.) per gram, these dat,a emphasize the unrrliabi1it.y of the latter treat,ment as a method for the determination of superoxide oxygen. Hoxever, George ( I ) has reported that treatment of potassium superoxide with water at room teinperatue causes release of the theoret'ical quantity of oxygen required for conversion to peroxide. The authors are unztble t o sc.count for the discrepancy between his results nith potasGum superoxide anti theirs with the sodium compound. ACKNOWLEDGRIENr
The authors are indebted t o the Office of Saval Research for a grant which has made this aiid continuing investigations possible. LITERATCRE CITED (1) Gcoi.ge, Discnssio~zsFaraday SOC.,KO.2, 196 (1917). (2) Holt and Sims, J . Chem. Soc., 65, 433 (1894). ( 3 ) Kaaartiovskii et al., D o k l a d y Aknd. S a u k , S.S.S.R., 64, 69 (1919). f4) Kram and Parmenter, J . Am. Chem. Soc., 56,2385 (1934). (5) Steyhanou, Ph.D. thesis, Cniversity of Kansas, 1949. 16) Stephanou, Schechter, Argersinger, and Kleinherg, J . rim. Chem. SOC.,71,1819 (1949). (7) Whaley and Kleinberg, Ibid., in press.
RECEIVED M a y 19, 1950.
Determination of Hydroxy Compounds in Amine Mixtures SIDNEY SIGGIA AND IRENE R . KERVENSKI General Aniline a n d F i l m Corp., Euston, P a .
.4 method was necessary for determining alcohols in amine mixtures in order to follow the alkylation of amines with alcohols. By acetylating the mixture, the alcohol is converted to the ester and the primary and secondary amines to the corresponding amides. The ester can be quantitatively saponified without significantly affecting the amides. High degrees of accuracy and precision are attainable. It is now possible to determine hydroxy compounds in the presence of amines without significant interference. This was previously impossible chemically except in isolated rases.
0
S E of the most satisfactory methods of determining hydroxy
compounds is acetylation. Primary and secondary amines constitute an interference because they also acetylate (4). \litcliell, Hawkins, and Smith ( 3 ) devised a method for determining hydroxyl groups in the presence of amines by esterification with an acid, using boron trifluoride as a catalyst. They measured the water formed on the esterification via the Karl Fischer reagent. The procedure described below consists of acetylating the mixture quantitatively by the procedure of Ogg, Porter, and Willits (6). The primary and secondary amines acetylate t o the corresponding acetyl compound, and the hydroxy compounds acetylate to the esters. The samples are brought just to neutrality and then an excess of standard alkali is added for saponification. The ester saponifies quantitatively, whereas the acetylated amines are not affected. This technique of acetylation and then saponification was
employed by several analysts ( 1 , 2, 7 ) in the dcterniination of hydroxylated fatty acids. The same grneral approach was found to be applicable for hydroxyl groups in the presence of amines. The primary and secondary amine content can also be determined in the system. Because these compounds acetylate quantitatively, by subtracting the anhydride consumcd by thr hydroxy compound from the total anhydride consumed, a value can be obtained for the primary plus secondary amine content of the samplr If the content of the various amines in the sdmplc is desired, the procedure of Siggia, Hanna, and Kervenski (6) or of Wagner, Brown, and Prters (8) can be used. REAGENTS
Acetylation reagent, 3 parts of pyridine to 1 part of acetic anhydride. Standard alcoholic sodium hydroxide, 0.5 A'. Approximately
