以溴代十六烷基吡啶为增敏剂催化动力学光度法测定痕量钴(Ⅱ)

Catalytic Spectrophotometric Method for Determination of Trace Cobalt(Ⅱ) with Cetyl Pyridine Bromide as Sensitizet

在增敏剂溴代十六烷基吡啶和活化剂氨基乙酸存在下,钴对高碘酸钾氧化酸性铬兰K的反应具有催化作用,据此建立了一种测定痕量钴(Ⅱ)的新方法。考察该反应的最佳条件,测定反应动力学参数。在表面活性剂和活化剂存在下,本法灵敏度提高12倍。线性范围为0～100μg/L,检出限为9.06×10-7g/L。此法用于茶叶、VB12等样品中钴的测定,结果令人满意。

A new catalytic spectrophotometrin method for the determination of trace amounts of Co（ Ⅱ ） has been developed. The method is based on the catalytic effect of Cobalt（ Ⅱ）on oxidation of acid chrome blue K by potassium periodate with aminoacetic acid as an activator and cationic surfactant of cetyl pyridine bromide（CPB） as a sensitizer. The optimum conditions of reaction and kinetic parameters were assayed. On the optimum experimental conditions, the linear range is 0-100 μg/L, and the detection limit is 9.06× 10^-7 g/L. The sensitivity is increased by 12 times in the absence of the surfactant and activetor. The method can be used for the determination of cobalt（Ⅱ） in tea and Vitamin B 12 samples with satisfactory results.