三辛烷叔胺萃取分光光度法测定水中钍

Study on the Determination of Thorium in Water by Trioctyl Tertiary Amine Extraction Spectrophotometry

采用氢氧化铁共沉淀载带水中钍,经浓硝酸溶解沉淀后,采用三辛烷基叔胺(N-235)混匀溶液萃取,盐酸反萃取,进一步纯化分离钍,与铀试剂Ⅲ形成络合物后用分光光度法测定。方法在0. 05 mg/L～0. 500 mg/L范围内线性良好,方法检出限为0. 025μg/L,探测下限为0. 10μg/L。将该方法用于实际水样的测定,6次测定结果的RSD为7. 0%～19. 6%,回收率为90. 0%～92. 4%。

Thorium in water was concentrated by Fe(OH)3 coprecipitation. The precipitate was dissolved in concentrated HNO3 . With trioctyl tertiary amine (N-235) extraction and hydrochloric acid reextraction for further separation, thorium was then determined by spectrophotometry using uranium reagent Ⅲ. The method had good linearity in the range of 0.05 mg/L to 0.500 mg/L. The method detection limit was 0.025 μg/L and the lower limit of quantitation was 0.10 μg/L. Applied this method to practical water sample determination, the RSDs of six duplicated measurements were from 7.0% to 19.6%, and the recoveries were from 90.0% to 92.4%.