V O L U M E 23, NO. 4, A P R I L 1 9 5 1 The adsorption by talc and kaolin was investigated by Oksent'yan ( 3 ) . H e concluded that differences in adsorption were caused by the different negative charges on the adsorbents. Observations in this laboratory have suggested that adsorption depends on the number and position of the anionic functional groups (-SOJ- or -COO-) in the molecule. The chromatography on talc of various classes of dyes is being investigated t o determine the mechanism of adporption. EXPERIMEhTA L
Electrophoresis. The procedure and apparatus described by Strain (10) were employed. Preparation of Dye Samples. I n the cmes marked with an asterisk, the commercial dye samples were extracted with dimethyl formamide t o separate the soluble dyes from a residue of insoluble inorganic salts. The extracts were evaporated until crystallization occurred recrystallized sample of Orange I1 was obtained from Eastman. The other samples were kindly supplied by AIrs. Philip Bradley of the dye testing laboratory at Easton. The chromatograms which were obtained using recrystallized samples were similar t o those from the commercial dyes. ,4 sample (2 t o 5 mg.) of each dye was dissolved in about 5 ml. of water. ITsually about 1 t o 2 ml. of the solutions were taken for a chromatogram. Chromatography. The adsorbent was prepared in a water slurry by mixing 1 part of talc (U.S.P. powder, J . T . Baker Chemical Co.) with 2 parts by n-(Jight of Hyflo Super-Crl (Johns-
673 blanville). The adsorbent slurry was poured in a Tswett chromatographic tube (No. 11, 200 mm. in length) and washed with water until it had packed into a n even column. A small disk of filter paper was placed on the top of the adsorbent. The dye sample wa.s poured on the column and developed with pyridine (0 t o lornc) in water. The zones were eluted with pyridine, ethyl alcohol, or water. ACKNOWLEDGMENT
The authors are grateful t o L. T . Hallett of this laboratory for reading the manuscript and encouraging publication of this work. LITERATURE CITED
(1) Karabinos, J. T., a n d H y d e , P. hf., J . Am. Chenz. Soc., 70,428 (1948). (2) Kolthoff, I. A I . . Pharm. W'eekblad, 56, 224-6 (1919). (3) Oksent'yan, U . G . , Mi'crobiology, C.S.S.R., 9, Xo. 1 , 13-14, E n g . (1940). (4) Rohland, P., Furbcr~-Ztg.,18, 1229. (5) Rohland, P., Kolloid-Z., 15, 180-2 (1914). (6) Rohland, P., Seijenfnbr., 35,459-61 (1915). (7) Rowe, F. M., e d . , "C'olour I n d e x , " New Y o r k , D. T a n Xostrand Co., 1924. (8) Ruggli, P., a n d Jensen, P., Hclr. Chiin. Acta, 18, 624 (1936). (9) Ibid., 19, 64 (1936). (10) Strain, H. H., J . Am. ('henz. Soc., 61, 1293 (1939). (11) Wykspiel, I. F., K l e p i i g ' s I'ertil Z., 45, 1035 (1940). RECEIVED July 12, 1950.
Infrared Determination of Methyl Deuteride Application to Analysis of Deuterium Oxide THEODORE L. BROWN AKD RICHARD B. BERNSTEIN Illinois Institute of Technology, Chicago 16, I l l .
HIS note reports a n infrared spectrophotometric method for Tthe determination of methane-d (methyl deuteride, CHID) in methane, and its application t o the determination of deuterium in water.
slit drive was found to be more satisfactory than operation with a fixed slit width because of the large slope of the curve of emission us. wave length for the source. The average deviation of the repeated absorbancy measurements taken for a single gas sample was *1%.
The methyl deuteride fundamental absorption band occurring
at 2204 cm.-l was chosen for the analysis. Base line technique was employed. A Perkin-Elmer Model 12C spectrophotometer with sodium chloride optics and a 10-cm. cell was used. The analytical peak was scanned approximately six times a t the slowest speed of the wive-length drive. The continuous slit drive was so scheduled that the slit width was 0.062 mm. a t the analytical wave length. Because of the low dispersion of the prism in this region, and the resulting strong dependence of the absorbancy on the slit width, it was necessary t o exercise care t o reproduce the slit drive schedule fioni time t o time. Use of the
PARTIAL PRESSURE
OF CHID,MM. HG
Figure 1
T a b l e I.
Slimmar> of Experimental D a t a Pmm
Pmm.
% DzO
(Total)
(CHsD)
Absorbancy
98.0 90.0 90.0 90.0 90.0 90.0 33.8 98.0 33.8 90.0 13.6 98.0 33 8 98.0 4.0
149 149 140 129 89.7 89.2 198 56.8
146 134 1'76 116 80.6 80.3 07.0 55.7 53.5 48.9 40.2 31.0 16.9
0.109 0.102 0.107 0,089 0.071 0.070 0,064 0,058 0,054 0,049 0,042 0,033 0.021 0.019 0.011
1;s
34.4 296 31.7 50.0 14.1 247
13.8
9 . $1
Figure 1 shoirs the results obtained for binary mixtures of methyl deuteride and nirthane. The absorbancy of the 2204 em.-' band of methyl deuteride is plotted against the partial pressure of methyl deuteride. The curvature is similar to that found by Coggeshall and Saier ( 1 ) for methane. The average deviation of points from the experimental curve is + 4 % in terms of partial pressure. Table I summarizes the experimental data. The columns list, respectively, the percentage of deuterium oxide taken, the total pressure of isotopic methanes (mm. j , the calculated partial pressure of methyl deuteride, and the averagr absorbancy of the 2204 cm.-' band.
ANALYTICAL CHEMISTRY
674
The mixtures of methyl deuteride and methane were obtained from the reaction of deuterium oxide-water mixtures with methyl magnesium iodide (ca. 3 LV in dibutyl ether), carried out in a vacuum system. The water samples ranging in size from 20 to 200 mg. were distilled in vacuo onto the previously degassed and frozen Grignard reagent. The methane liberated after warming was transferred by a Toepler pump, past a dry ice trap, into the gas ~ ~ 1 1The . total methane pressure in the cell was recorded.
If the rates of reaction of deuterium oxide and water with the Grignard reagent are the same, the per cent methyl deuteride in the methane is equal to the atom per cent deuterium in the water. Orchin, Render, and Friedel ( 2 ) showed this to be the case in connection with their work on the analysis of deuterium oxidewater mixtures. Their method was based on mass spectrometric examination of the methyl deuteride-methane mixtures formed after the water reaction with the Grignard reagent in a nitrogen atmosphere. In the present study five different concentrations of deuterium oxide were used, ranging from 4 to 98 atom % ' deuterium For each sample of mixed isotopic methanes thus produced, several points of the calibration curve of Figure 1 could be obtained, by successive reductions of the total pressure. Coggeshall and Saier ( I ) , who studied the dependence of the absorbancy of the 7.65 fi band of methane upon the partial pressure of nonabsorbing foreign gases, found a considerable pressure-broadening effect. In the present study the presence of air as a foreign gas was found to cause an appreciable increase in apparent absorbancy, as
anticipat,ed from their results. Although no systematic study was carried out to determine the pressure-broadening effect due to methane, the data of Table I suggest that this may be small. No trend or scatter associated with the variation of total methane pressure is evident from Figure 1. The minimum limit of detectability of methyl deuteride in methane (and thus of deuterium oxide in water) was investigated using samples of approximately 1% deuterium oxide. For a 100mg. sample, 0.4 atom % deuterium may be detected with certainty. The ultiniat,e sensitivity of the method appears limited by the instrumental noise-to-signal ratio. Under the conditions used, this was generally about 0.5%. It would appear that the infrared method described would lie suitable for estimation of deuterium in small quantities of water. ACKNOWLEDGhIENT
The deuterium oxide was procured through the courtesy of the Atomic Energy Commission. The aut,hors appreciate thc assistance of S. Kxta and D. rr. Kniebes of the Institute of Gas Technology. LITERATURE CITED
(1) Coggeshall, S . D., and Saier, E. L., J. A p p l i e d P h y s . , 17, 450 (1946). (2) Orchin, ll.,\Vender, I., and Friedel, R. A., ANAL.C m x , 21, 1072 (1949). RECEIVED .June 23, 1550.
Microdetermination of Total Phosphorus by Amperometric Titration RICHARD N. BOOS A h D JOHN B. CONY Research Laboratories, Werrk & Co., Inc., Rahway, .V. J .
METHOD for the determination of total phosphorus in
Li organic compounds based on the Kolthoff and Cohn ( I ) amperometric titration of phosphate ion with uranyl acetate hap been developed, and is now in routine use. Bolthoff m d Cohn ( 1 ) showed that the concentration of SUIfate in the solution to be titrated must be less than 0.01 .%I This limitation forces the abandonment of wet combustion Fusion of the organic compound methods using sulfuric &id. with sodium carbonate is satisfactory f i om the standpoint of speed, accuracy, and ease of handling. The total phosphorus content can be determined within 45 minutes by the proposed procedure, the economy in time being a matter of many hours in comparison with the gravimetric method. It was observed that when the concentration of phosphate in the solution to be titrated was in the range of 0.0005 M , the curve obtained was irregular in the vicinity of the equivalence point. This difficulty wm caused by crystallizrttion of the initially amorphous precipitate of uranyl potassium phosphate, and was eliminated by the addition of a few crystals of uranyl potassium phosphate to saturate the solution before the start of the titration. Cocarboxylase was used as a standard compound in testing the feasibility of the method. The cocarbovylase was found pure by solubihty analysis and the analytical results for the anhydrous material were as follows: Carbon Hydrogen Nitrogen Chlorine Phosphorus
Calcd.
Found
31.25 4.16 12.16 7.69 13.20
31.50 4.27
12,25
flask with 300 ml. of water and 6 to 10 ml. of glacial acetic acid, I t is diluted with water to 1 liter. Standard Phosphate Solution. Potassium Phosphate Monobasic Merck (Soerensen's potassium phosphate) is dried a t 110' C. for 1 hour and a 0.001 M solution is prepared by dissolving 136.14 mg. in water and diluting to 1 liter. Potassium chloride, 2 -If. Acetic acid, 0.1 M . Sodium carbonate anhydrous, Nerck. Bromocresol green indicator solution, 0.04% (Clark and Lubs solution). Hydrochloric acid, 5 -V and 0.5 dV. Cranyl potassium phosphate is prepared by mixing 50 ml. of 0.01 M potassium dihydrogen phosphate, 5 ml. of 0.1 M acetic acid, 5 ml. of 2 M potassium chloride, 20 ml. 95% ethyl alcohol, 20 ml. of distilled water, and 4.83 ml. of 0.1 M uranyl acetate. The precipitate is allowed to stand overnight, after which it is filtered and washed with 0.1 M acetic acid, distilled water, and acetone. The precipitate is dried for 1 hour in a vacuum desiccator. PROCEDURE
The sample is weighed into a 5-ml. platinum crucible and covered with approximately 100 mg. of sodium carbonate. The
Table I. Sample Cocarboxylase Cocarboxylase Cocarboxylase A
7.63 1 3 . 0 1 (gravimetric)
Samples A, B, C, D, E, and F listed in Table I represent samples of other organic compounds that were submitted by chemists in these research laboratories. REAGENTS
Uranyl acetate, 0.1 31, is prepared by dissolving 42.422 grams of uranyl acetate monohydrate in a 1-liter volumetric
B C
n E
F
Determination of Total Phosphorus Volume Sample U O ~ ( A c ) ~ , MI. Calcd.
W L ,J l g .
3.455" 0.0568 0.0480 1.188 0.0244 0.622 5.9~32~ 0.684 1.029 0,0289 0.664 0.0175 2 108 0,0288 586 0.0511 - , 410 0,0521 4.680 0.01896
;: 8p;;
$,
13.20
...
Gravimetric
dmperometric
13.01
13.16 12.95 12.60 i.05
...
,.. 6.80
6.94
9:06
8.69
i.35 9.00
4.43
8.62 4.38 16.61
...
4.59 16.85 6.82 2.23
, . .
...
...
... ...
6.g3
... 2.28 Xeutral solution was diluted to 10 ml., 4 ml. of which wae transferred t o titration cell 0.1043 .II 'ZTOn(Ac)*. Other resulta n'ere obtained using 0.1034 ,If a
*
UOi(Ac)s.
