极谱法同时测定岩石中的微量铀钍

Simultaneous determination of micro uranium and thorium in rocks by polarography

试样经过氧化钠熔融后，用硝酸溶液提取熔块，加入十六烷基三甲基溴化铵（CTMAB）凝聚硅胶，过滤除硅，TBP萃淋树脂分离富集铀钍。在含0．02g／L四丁基碘化铵-4g／L铜铁试剂、pH=5的乙酸-乙酸钠极谱测定体系中同时测定铀钍，铀钍的线性范围为0．001～0．500μg／10mL。本法用于含铀岩石中微量铀钍的同时测定，结果令人满意。

A method for the simultaneous determination of micro uranium and thorium in rocks by polarography is reported in this paper. Sample was fused with Na2O2 and the fusion cake was digested with nitric acid solutions. Cetyl trimethyl ammonium bromide was added into the soiution to coacervate silica gel. After remove the silicon by filter, uranium and thorium were separated and enriched by CL-TBP extraction resin. Then micro uranium and thorium were determinated simultaneously in a buffer solution of acetic acid-sodium acetate of pH=5 and with 0.02 g/L tetrabutyliodic ammonium and 4 g/L cupferron. The linear range of uranium and thorium is 0. 001--0. 500μg/10 mL. The method has been applied to the simultaneous determination of micro uranium and thorium in rocks with satisfactory results.