海洋样品中^(231)Pa和U,Th同位素的联合分离测定

STEPWISE SEPARATION AND DETERMINATION OF (231)~pa ISOTOPES OF U AND Th IN MARINE SAMPLES

本文结合已报道的U,Th分离方法和^(231)Pa分离条件建立了Th-Pa-U联合分离流程和测试技术,并用以分离测定一个锰结核和一个深海沉积物样品中的^(231)Pa,U和Th同位素含量的深度分布。用^(231)pa_(ex),^(230)Th_(ex)和^(230)Th_(ex)/^(232)Th法分别计算该锰结核的生长速率为1.5,0.9和1.5mm/Ma。U,Th和^(231)Pa的化学回收率(％)分别为40—80,80—92和60—86。

Combing the published method of determing isotopes of U and Th with the condition of separating 231Pa, a new method was established to separate and determinate 231Pa, isotopes of U and Th simultaneouly.The profiles of U, Th and 231Pa in a deep-sea manganese nodule and in a sample of the deep-sea sediment were determined, respectively, using the method. The growth rates of the manganese nodule were 1.5, 0.9 and 1.2mm/M.yr. separately, through the methods of 231Paex, 230Thex and 230Thex/232Th. The recoveries of U, Th and 231Pa were in the range of 40-80, 80-92 and 60-86% respectively.