曙红B催化动力学光度法测定痕量铋(Ⅲ)

Determination of trace bismuth(Ⅲ) by catalytic kinetics spectrophotometry with bromeosin B

在硫酸介质中,铋(Ⅲ)对碘酸钾氧化生物染料曙红B的褪色反应有强烈的催化作用,据此建立了测定痕量铋(Ⅲ)的催化动力学新方法。体系催化反应吸光度(A)和非催化反应吸光度(A0)的变化值(ΔA)与铋(Ⅲ)浓度在0.2～1.2 mg/L范围内呈良好的线性关系。方法检出限为7.22×10-11 g/L,表观速率常数为2.97×10-4 s-1,表观活化能为36.74 kJ/mol。将该法用于水体中痕量铋(Ⅲ)的测定,结果满意,回收率为98.5%～104.2%。

In H2SO4 media,bismuth（Ⅲ） has strong catalytic effect on the decolorizing reaction of potassium iodate oxidizing biological dyestuff,bromeosin B.According to this phenomenon,a new method of trace bismuth（Ⅲ） de-termination by catalytic kinetics has been established hereby.The absorbency variation value ΔA of system catalytic reaction（A） and non-catalytic reaction（A0） have good linear relationship with bismuth（Ⅲ） whose mass concentration is in the range of 0.2-1.2 mg/L,and the detection limits is 7.22×10-11 g/L.The apparent velocity con-stant is 2.97×10-4 s-1,and apparent activated energy is 36.74 kJ/mol.The method has been applied to the determina-tion of trace bismuth（Ⅲ） in water body.The results are satisfactory and its recovery rate is 98.5%-104.2%.