催化动力学光度法测定锡-钴-锌三元合金镀液中的钴

Determination of Cobalt in Tin-Cobalt-Zinc Alloy Plating Bath by Catalytic Dynamic Spectrophotometric Method

在HC l介质、沸水浴中,Co2+能催化铋酸钠氧化硫堇褪色反应,据此建立了催化动力学光度法测定Co2+的新方法。Co2+在0~50μg/mL范围内遵守比尔定律,表观摩尔吸光系数为3.494×104L.mol/cm,检出限量为0.052 05μg/mL。该催化反应用于锡-钴-锌三元合金镀液中钴含量的测定,结果令人满意。

A new determination method of Co^(2+) was built according to the oxidation fading reaction of sodium bismuthate and thionine catalyzed by Co^(2+) in boiling hydrochloride solution.Beer' law was obeyed as Co^(2+) concentration is in the region of 0~50 μg/mL,the apparent molar absorptivity is 3.494×10~4(L·mol/cm),and the detection limit is 0.052 05 μg/mL.The method can be used in concentration determination of Co^(2+) in Sn-Co-Zn alloy plating bath with satisfactory result.