amounts to the solution heing titrated. I'lic sen.iti\ity of FeA2 to oxidation hy gamma radiation is high ( I ) . Since the method depends on the change in the oxidation potvntial of the Fe+* ~ 1 2it is changed to the Fe(FXW.t)2-2 cwmplex, the radiztion interferes b y ~ m m a t u r e l yoxidizing tlie Fe L2. The Linil)eronietriccurrent, rather than being ~-mtially con,-taiLt before the end ;)oint, increaheq gradually, and no h r p hrenk is olltained at the end ,mint. It iq ther:fore recoinmended t liat in radiation field. of intendty
(6) Kelley, AI T , ilIiller, H H I Zbzd
greater than lo3 r., the VO+*procedure be used whenever possible.
,
24,1895 (1952) (7) Ringbom, A , Kilkman, B , ilcta Chem Scand 3, 22 (1949)
Y B , Bricker, C E , ANAL.CHEM.26, 19; (1954). ( 9 ) Weiss, J., Allen, A. 0.: Schm-arz, €1. A,, Proc. I n f e m . Conj. Peaceful C'srs At. Energy, Genera 14, 179 (19:5). (10) Kelcher, F. J., "The Analytical Cses of Ethglenediaminetetraacetic Acid," Van Sostrand, Princeton, S . J., 1958. RECEIVEDfor reviex hIurch 26, 1963. *lcc.epted June 2 S , 1Y63. Oak Ridge Kational Laboratory is operated by Union Carbide Corp. for the L-. S. Atomic Energy Coniniisuion. 18) Sneetser.
LITERATURE CITED
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(1) Allen, A . O., "The Radiation Chemistry of FVater and Aqueous Solutions," F-an Sostrand, Princeton, K. J., 1961. ( 2 ) Dale, JV. M., Gray, L. I
