ported e n i i t t d wavrlength, but the P P O solvents did not have noticeable lobses, and at room temperature the balance Iioinlzi for the C14 were higher when the filter was employed. The filter was observed to markedly r d u c r the count of blank and C1* s a n q i l ( ~upon esl)osure to light. I’pon 2-mini~tedark adaptiorl the blank count had returned to the previous value n-hich was obtained u1)on 24-hour dark adaptation. I t is reasonable to speculate that the use of the filter would afford lower background with less fluctuation in counting samples where chemiluminescence is a problem. This applica,tion would be of great w l u e in liquid scintillation counting. LITERATURE CITED
W.,AucZeon?cs 15 (10) 106 (19.57). ( 2 ) Anderson, B. C., Arnold, J. R., Libby, \!-. F., Rev. Scz. fnstr. 22, 225 (1951). 1 3 ) Arnold, J . R . , “Licluid Scintillation Countincr.” D. ‘129. Peraamon Press, k e w YoFk, lb58. (1) iigranoff, B.
(4) Audric, B. N., Long, J. V., J . Sei. K. H., Symposium on the Detection f n s t r . 30, 467 (1953). and Uses of Tritium in the Physical and (5) Barendsen, G. W., A‘ucleonics 16, Biological Sciences, International Atomic Energy Agency, Vienna, p. (11) 197 (1958). (6) Bibron, R., Delibrias, G., Leger, C., 263, 1962. Proc. Intern. SvmDosium on Nuclear (18) Mayneord, W., Anderson, H. D., Electronics, Yo!. iI, p. 157, InterRosen, D., Radiation Research 3, 379 national Atomic Energy Agency, (1955). Vienna, 1959. (19) Miller, C. E., Marinelli, L. D., ( 7 ) Boyce, I. S., Cameron, J. F., “SymRowland, R. E., Jose, J. E., Il’ucleonics posium on the Detection and Uses of 14 (4)40 (1956). Tritium in the Physical and Biological (20) Packard, L. E.. “Liquid Scintillation Sciences.” p. 231, International -%tomic Counting,” p. 50, Pergamon Press, New York, 1958. Energy Agency, !.ienna, 1962. (8) Davidson, J. D., Fiegelson, P., Intern. (21) Perrin, F., Ann. Phys. 12, 169 (1929). (22) Rapkin, E., Gibbs, J. A., Intern. J . J . Appl. Radiation Isotopes 2, 1 (1957). (9) Drew, H. D., Trans. Faraday SOC. Appl. Radiation Isotopes 14, 71 (1963). 35, 207 (1939). (23) Roucayrol, J. C., Oberhaussen, E., (10) Godfrey, T. N., Harrison, F. B., Science 122, 201 (1955). (24) Sangster, R. C., Irvine, J. W., J . Keuffel, J. W., Phys. Rev. 84, 1248 (1951). Chem. Phys. 24, 670 (1956). i l l ) Haves. F. S . . Hiebert. R. D.. (25) Sawyer, G. A., Wiedenbeck, M. L., SchucL, R. L., Scihnce 116, 140 (1952): Phys. Rev. 79, 490 (1959). (12) Herberg, R. J., Ibid., 128, 199 (1958). (26) Sharp, J., Thomson, E. E., “Proc. (13) Hodgson, T. S., Gorden, B. E., 2nd Intern. Conf. on the Peaceful Uses of Atomic Energy,” Geneva, Ackermin, 52. E., L\rucleonics 16 (. 7,) 89 (1958). 1958. 114) Kasha. M.,Chem. Rev.41.401 11947). (27) Swank, R. K., “Liquid Scintillation ( i 5 j Firsten, F. A., Proc. Second ~ y i Counting,” p. 23, Pergamon Press, Kew York, 1958. posium on Advances in Fast-Pulse Techniques for Nuclear Counting, Berkley, UCRL-8706, 1959. RECEIVEDfor review April 27, 1964. (16) Lanter, R. J., Corwin, R. W., Rev. Accepted July 10, 1964. Second Annual Sci.Instr. 23, 507 (1952). Oak Ridge Radioisotope Conference, April (17) Lloyd, R. A., Ellis, S. C., Hallowes, 20, 1964, Gatlinburg, Tenn. ~
Emission Spectrographic Determination of Boron in Plutonium and Uranium Nitrate Solutions Following Cation Exchange Separation ALBERT W. WENZEL aiid CHARLES E. PlETRl
U.
S. Afomic
Energy Commission, New Brunswick, N. 1.
b Trace amounts of boron are determined b y emission spectrography following separation from plutonium or uranium in dilute nitric acid by cation exchange. Mannitol complexing is used to prevent boron losses upon concentration of the boron-rich effluent b y evaporation to dryness prior to the spectrographic determination. Boron is subsequently determined using a zinc internal standard and an indium oxide matrix b y excitation in a d.c. arc. The lower limit of detection varies from 0.007 to 0.001 kg. of boron depending upon the instrumental setup. The rellative standard deviation for 0.1 to ;!-gram uranium samples in the 0.1 to 30-p.p.m. range and 0.1- to 0.4-gram plutonium samples in the 3- to 30-p.13.m. range was within 9% while a t the 0.05-p.p.m. level in 2 grams of uranium it was 1 2y0. Within experimental limits complete recovery of boron in all synthetic samples was obtained a t all levels. The influence of the boron blank values a t the 1 to 0.1 -pg. level is discussed.
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T
of impurities have been separated from interfering plutonium and uranium for spectrographic analysis by anion exchange methods. These procedures employ 6 to 12N hydrochloric acid ( 2 ) or 8N nitric acid (6, I I ) , and the subsequent concentration of the impurity-rich effluent by evaporation to dryness causes partial or even complete loss of the more volatile elements such as boron. In many instances this loss may not be detected when both samples and standards are processed similarly. The total amount of boron available for determination, however, may be considerably reduced thereby substantially decreasing the spectrographic sensitivity for this element. An earlier attempt was made to prevent this loss of boron by using a mannitol complexing technique ( 5 ) but the amount of mannitol required for 8 S nitric acid solutions was excessive and made the spectrographic determination unreliable a t times (12). A method was required which would quantitatively separate microgram RACE A h f o c x T s
amounts, or less, of boron from plutonium and uranium without loss prior to emission spectrographic determination. Previous work with silicon indicated that boron could be separated from plutonium by cation exchange in 0.2.V nitric acid ( I O ) . Eberle, Lerner, and Kramer ( 4 ) , and Barnett and Milner ( I ) used a similar separation for the removal of uranium prior to boron determination by colorimetry or titration. ;\ccordingly, a cation exchange separation of plutonium and uranium from boron was investigated using mannitol complexing in the evaporation of the effluent from the separation step since much less mannitol was reqnired for 0.2N nitric acid than for the 8N acid solutions previously used. EXPERIMENTAL
Apparatus and Reagents. The glove boxes used for handling plutonium, the ion exchange column used for the separations, and tmheemission spectrographic equipment used for the boron determination have been previously described in detail ( I O ) . VOL. 36, NO. 1 1 , OCTOBER 1964
2083
tonium solutions containing the following impurities (in 1i.p.m.): h g ( < l ) , A1 (8), I3 (
