催化动力学光度法测定活化剂铝

本文研究了在pH5.0的醋酸-醋酸钠缓冲介质中,利用铝(Ⅲ)活化铜(Ⅱ)催化过氧化氢氧化邻苯二酚显色的指示反应,通过测量邻苯二酚氧化产物在360nm下吸光度的增加,建立了测定活化剂铝的催化动力学光度分析新方法。并对测量波长、试剂的浓度、反应温度、反应时间及共存离子的干扰等条件进行了探讨和选择。在最佳实验条件下,测定的线性范围为0.0040～0.20mg·L~(-1),方法的检出限为8.2×10~(-7)g·L~(-1)。结合双硫腙-四氯化碳溶液萃取分离,该法用于水样中和茶叶中铝含量的测定,结果满意。

Determination of Activator Aluminum by Catalytic Kinetic Spectrophotometry

In this paper, a new catalytic kinetic spectrophotometric method for the determination of activator aluminum was studied. The method was based on the activation effect of aluminum (III) on the copper (II) which catalyzes the oxidation of pyrocatechol by hydrogen peroxide in acetic acid-sodium acetate buffer solution at pH 5.0. The increase in absorbance of pyrocatechol oxidation product was monitored at 360 nm. The optimization of the operating conditions regarding measuring wavelength, concentrations of the reagents, reaction temperature, reaction time and interfering ions were also investigated and chosen. Under the optimum experimental conditions, the linear range of the determination was 0.0040-0.20 mg.L-1, the detection limit of the method was 8.2 x 10(-7) g.L-1. Combined with separation of extraction of dithizone-carbon tetrachloride solution, the method was applied to the determination of aluminum in water and tea samples with satisfactory results.