【摘要】 本文研究了钍（Ⅳ）与CPA-pN的显色反应,表明钍与配体的络合比为1:3,络合物在0—50μg/25ml呈线性关系,此蓝色络合物的最大吸收在680nm,摩尔吸光系数为7.55×10⁴cm^-1·mol^-1·1。在有CTMAB或CTMAB及乙醇存在下,其ε₆₈₀分别为1.35×10⁵和1.75×10⁵cm^-1·mol^-1·1,0—17.5μg/25ml和0—15μg/25ml服从比尔定律。在有过量CTMAB存在下,Th（Ⅳ）与CPA-pN的络合比为1:6。试验了外来离子对钍测定的影响。提出的方法曾用于微量钍的测定,结果满意。更多还原

【Abstract】 In this paper, the color reaction of thorium(Ⅳ )with chlorophosphonazo -pN ( CPA-pN ) has been investigated under different condition. It show’s that the ratio of metal to ligand is 1:3 and the asborbance of Th(Ⅳ) complex is linear in the range of 0-50μg Th/25ml. The blue complex has a maximum absorptioa at 680nm and its molar absorptivity is 7.55×10~4cm~1 ·mole~1 ·1. The molar absorptivity in the presence of CTMAB or CTMAB and alcohol is 1.35×10~5 and 1.75× 10~5cm~1·mol~1 ·1, respectively, and both their maximum absorption are 680nm . Beer’s law is obeyed in the range of 0-17.5μg Th/25ml and 0-15μg Th/25ml , respectively . The ratio of Th(Ⅳ)to CPA -pN in the precence of exceed CTMAB is 1:6. The effects of foreign ions on the determination of thorium ( Ⅳ ) have been examined. The proposed methods were applied for the determination of trace Th, and the results were satisfactory.更多还原