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 Arsenazc Ⅲ as Color Reagent and Sensitized by the Synergic Action of Triton X-100 and β-Cyclodextrin

摘要: 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50 mL的溶液中含0.02 mol·L-1盐酸溶液0.20 mL,0.5%曲拉通X-100溶液4.0 mL,0.01 mol·L-1 β-环糊精溶液2.0 mL及500.0 mg·L-1偶氮胂Ⅲ溶液2.0 mL的条件下进行显色反应,反应经25 min完成.该络合物的最大吸收波长为652 nm,镧(Ⅲ)的质量浓度在0.20~100.0 mg·L-1范围内符合比耳定律,检出限(3S/N)为0.20 mg·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.

Abstract: A method of spectrophotometric determination of lanthanum(Ⅲ) was proposed.Arsenazo Ⅲ was used as color reagent and sensitized by the synergic action of Triton X-100 and β-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 arsenazo Ⅲ solution 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%.