本文研究了钍(Ⅳ)与3′-竣基偶氮氯膦(CPAmK)的显色反应,在0.64mol·L~(-1)HCl介质中,Th(Ⅳ)与CPAnK形式各合此为1:3的蓝色各合物,其浸大极(?)峰位于670nm,在范围内符合比尔定律。试验了30种外来离子对测定的干扰,在加入10ml10％草酸溶液作掩蔽剂时,近一半金属离子的容许存交量均达到(?)量的2500倍以上,其它常见金属离子的允许存在量也可达到250倍以上。叹Hf(Ⅳ)和R.E.(Ⅲ)有较大干扰。方去三用于合成试样的分析并进行了标准回收试验,结果令人满意。 In this paper, the color reaction of thorium (Ⅳ) with 3’-thiocarbocyanine (CPAmK) was studied. In 0.64mol·L -1 HCl medium, the combination of Th (Ⅳ) 1: 3 blue compounds, the dip pole (?) Peak at 670nm, in line with Bill’s law. When 30ml of 10% oxalic acid solution was used as the masking agent, nearly half of the allowable amount of metal ion was more than 2500 times (?), And the allowable amount of other common metal ions Can reach more than 250 times. Sigh Hf (Ⅳ) and R.E. (Ⅲ) have a greater interference. Fang to three for the synthesis of the sample analysis and conducted a standard recovery test, the results are satisfactory.