LITERATURE CITED
Table 11.
Standard Samples Run by Routine Procedure
Actual yc
(UsOs) Weight
Reported Sample New Brunswick No. 1 (phosphate rock)
for
Standard 0,029
of
Sample, G. 1.00 1.oo
Dev.
% Us08 Found
of BV.
0.024
from Reported Value -0 005
0,027
-0 002
0.180
0.000
0,110
-0 004
0.064
0 000
0.104
-0 005
0.00065
-0 00006
O.OOO75
0 00004
0.0148 0.0152
0,015
0 000
0.0178
0,018
-0 001
0.023
-0 001
0.012
OOOO
0.011
-0 001
Duplicate analyses 0.024 0.025 0,027" 0.0274
Av .
AEC 4
0.180
0.20b
5
0.114
0.25b
8
0.064
1.00
9
0.109
0.25a
0.00071 (17.1 p.p.m.)
5.00
Rubidoux Mtn. leucogranite
10.00
0.180 0.180 0,110 0.109 0.063" 0.06E1~
0.104
0.104 0.0006 0.0007 0.0007 0.0008
(1.1 Fisher. S.. Kunin. R.. A s . 4 ~ .CHEY.
. 29, 400'(1957). ' ' (2) Kraus, K. A., Moore, G. E., Kelson, F., J. Am. Chem. SOC.78,2692 (1956). (3) Seim, H. J., Morris, R. J., U. S. Atomic Energy Comm. Rept. RMO2682 (1958). (4) Seim, H. J., Morris, R. J., Frew, D. IT.,ANAL.CHEM. 29, 443 (1987). ( 5 ) Seim, H. J., Morris, R. J., Frew, D. W., U. S. Atomic Energy Comm., Rept. RMO-2680 (1956).
H. J. SEN R. J. MORRIS R. G. PASTORINO
Department of Chemistry University of Nevada Reno, Nev. COZDUCTED under Contract KO.AT(491)-624 between the U. S. Atomic Energy Commission and the University of Yevada, Llackay School of Mines.
Natl. Lead 1
0.015
2
0,019
3
0.024
1.00
4
0.012
1.00
3
0.012
1.00
h c
1.00 F
1.oo
0,0182 0.0225 0.0230 0.0120
0.0116 0.0113 0.0110
F'alues obtained by double column technique. Aliquots of 1.00- or 1.25-gram samples. Sample dissolved using H F and "03.
nip. per sample, a 100-ml. wash of 10-Y hydrochloric acid after adsorption usually eliminates the interference. For concmtrations above 100 mg., the double coliimii separation is recommended; thorium would not be a problem even in pucessive amounts, as it is not adsorbed on the resin in 1 0 s hydrochloric acid ( 2 ) . Phosphate rock containing in excess of 100 mg. of calcium phosphate per sample caused losses due to coprecipitation of uranium with calcium sulfate in the solution step. These losses n cre minimized by using the double colunin separation. I n 1 0 s hydrochloric acid, neither calcium nor phosphate was adsorbed on the resin. As uranium and iron were adsorbed, the effect of high concentrations of iron was studied. Iron concentrations in excess of 200 nig. per sample caused uranium leakage in a resin volume of 5 ml. I n such cases the resin volume should be increased. To determine the accuracy of the procedure, a series of uranium standards was analyzed, a majority obtained from the Colorado Plateau (Table 11). The reported uranium content of the New Brunswick and AEC standards is a statistical average from the results of several independent laboratories. The 958
ANALYTICAL CHEMISTRY
Rapid Spectrophotometric Determination of ManganeseTriethanolamine and Peroxide Complexes of Manganese(Ill)Correction procedure by Bruno [Accad. A pugliese xi., Atti e relaz. 11, Pt. 2, 409 (1953)] for the spectrophotometric PRIOR
leucogranite mas supplied by the California Institute of Technology and analyzed in replicate by independent analysts using chemical extractions and ultraviolet fluorescence. The National Lead samples are a series of fluorometric standards from Grand Junction, Colo. CONCLUSIONS
The procedure is adaptable to routine analyses and can be done with a niinimum of expense and equipment, especially in laboratories where ion exchange is in use or a fluorometer ip not available. Interferences from high thorium or calcium phosphate are minimized by double adsorption. Analytical detection may be expected for uranium concentrations as low as O . O O O l ~ O . The average deviation is 0.00270 or better for uranium values between 0.1 and 0.01%. For uranium values between 0.01 and O . O O l ~ o the accuracy of the determination is to approximately &lo%. ACKNOWLEDGMENT
The authors thank John K, Butler and his staff, Mackay School of Pliines, for suggestions and encouragement.
determination of manganese(I1) (sic) in alkaline triethanolamine solution is acknoKledged. This procedure recommended the determination a t 625 mp for solutions containing 5 to 30 y of manganese per ml., but the nature of the reduction and the identity of the colored species were not elucidated. The upper limit of 30 y per ml. for the Bruno method corresponds to our concentration limit of 0.5mM [AXAL. CHEar. 31, 146 (1959)], above which R-e could not effect the rapid quantitative air oxidation of the manganese(I1). For more concentrated solutions, the manganese(II1)-peroxide complex interferes and must be decomposed as described previously. The molar absorbance index of the manganese(II1)triethanolamine complex a t 625 mp is slightly greater than that at 438 mh, but the latter wave length provides a more specific method because copper(11) and iron(I1) do not interfere. I n spite of their simplicity, neither of these procedures can be recommended for concentrations less than about 1 m M because the molar absorbance of the manganese(II1)-triethanolamine complex is not sufficiently large to give accurate results; more sensitive procedures are available for dilute solutions.
E. R. NIGHTINGALE, JR.
