高碘酸钾-灿烂绿体系阻抑动力学光度法测定痕量铜

Determination of Trace Copper by Inhibition Kinetic Spectrophotometric Method with Potassium Periodate-brilliant Green System

在pH=4.0醋酸-醋酸钠缓冲介质中,铜(II)能阻抑高碘酸钾氧化灿烂绿的褪色反应,据此建立了阻抑动力学光度法测定铜(II)的新方法。在最佳测定条件下,铜(II)在0.05～2.0μg/mL范围内与催化反应速率呈良好的线性关系,检出限为0.008 9μg/mL。重复8次测定0.5μg/mL的铜(II),相对标准偏差为2.1%。大多数常见离子无干扰,用于钢铁中铜的测定,结果满意。

A kinetic spectrophotometric method for the determination of trace copper is proposed,based on the fact that Cu2＋ can sensitively inhibit the decoloration of brilliant green by potassium periodate in buffer medium of HAc-NaAc（pH=4.0）.The linear range is 0.05～2.0 μg/mL for Cu2＋ with the detection limit of 0.0089 μg/mL.The relative standard deviation was 2.1% for eight repeatedly determinations of 0.5 μg/mL copper.Most of the common ions do not interfere.The method has been applied to the determination trace of Cu2＋ in steel samples with satisfactory result.