催化甲基紫褪色光度法测定茶叶中的微量铁

Determination of Trace Iron in Tea by Photometry with Catalytic Decoloration of Methyl Violet

在稀硫酸介质中,微量铁对过氧化氢氧化甲基紫褪色反应具有强烈的催化作用,据此建立了催化褪色光度法测定微量铁的新方法。该方法线性范围为0.1—1.5μg/25mL,检出限为4.36×10-4μg/mL。可用于茶水中微量铁的测定,回收率在95.0%—101.6%之间,结果满意。

In dilute sulphuric acid,trace iron has strong catalytic effect on decoloration reaction of methyl violet by H_2O_2,based on this,a new method is established to determination of trace iron by catalytic decoloration photometric method.The linear range of the method was from 0.1μg/25mL to 1.5μg/25mL and detection limit was 4.36 X 10^（-4）mg/L.The method is applied to determination of trace iron in tea,and the recoveries of 95.0%—101.6%with satisfactory results.