曲拉通X-100与β-环糊精协同增敏-偶氮胂Ⅲ-分光光度法测定镧(Ⅲ)

Spectrophotometric Determination of Lanthanum(Ⅲ) with ArsenazcⅢas Color Reagent and Sensitized by the Synergic Action of Triton X-100 andβ-Cyclodextrin

提出了以偶氮胂Ⅲ作显色剂,曲拉通X-100与β-环糊精(β-CD)作协同增敏剂,分光光度法测定镧(Ⅲ)。在总体积为50mL的溶液中含0.02mol·L^(-1)盐酸溶液0.20mL,0.5%曲拉通X-100溶液4.0mL,0.01mol·L^(-1)β-环糊精溶液2.0mL及500.0mg·L^(-1)偶氮胂Ⅲ溶液2.0mL的条件下进行显色反应,反应经25min完成。该络合物的最大吸收波长为652nm,镧(Ⅲ)的质量浓度在0.20～100.0mg·L^(-1)范围内符合比耳定律,检出限(3S/N)为0.20mg·L^(-1)。方法用于合成试样中镧(Ⅲ)的测定,测定值的相对标准偏差(n=5)在2.1%～3.1%之间。

A method of spectrophotometric determination of lanthanum（Ⅲ） was proposed.ArsenazoⅢwas used as color reagent and sensitized by the synergic action of Triton X-100 andβ-CD.The color reaction was carried out in a solution containing 0.20 mL of 0.02 mol·L^（-1） HCl,4.0 mL of 0.5%Triton X-100 solution,2.0 mL of 0.01 mol·L^（-1）β-cyclodextrin,and 2.0 mL of 500.0 mg·L^（-1） arsenazoⅢsolution in a total volume of 50 mL. Twenty five min.were required for the completion of the color reaction.Beer＇s law was kept in the range of 0.20- 100.0 mg·L^（-1） when measured at the absorption maximum of 652 nm.Detection limit（3S/N） found were 0.20 mg·L^（-1） respectively.The proposed method was used in the determination of lanthanum（Ⅲ） ion in 3 simulated ore samples,with values of RSD＇s（n=5） in the range of 2.1%-3.1%.