三乙醇胺活化钴(Ⅱ)催化过硼酸钠氧化荔枝红色素褪色光度法测定痕量钴

Catalytic Spectrophotometry for the Determination of Trace Cobalt Based on Oxidizing Decoloration Reaction of Litchi Chinenses Red

基于三乙醇胺活化钴（Ⅱ）催化过硼酸钠氧化荔枝红色素的褪色反应，提出测定痕量钻的高灵敏的催化光度法。其摩尔吸光系数ε５００＝１．８×１０７Ｌ·ｍｏｌ－１·ｃｍ－１；线性范围为０～０．４μｇ／Ｌ；工作曲线的回归方程为；相关系数ｒ＝０．９９９８；检测限１．０×１０－１３ｇ／ｍＬ。该褪色反应的表观活化能 Ｅ＝４２．１２ ｋＪ·ｍｏｌ－１，速率常数 ｋ＝１，６×１０－３·ｓ－１。此法用于血清、尿液等样品中钻的测定，结果满意。

A highly sensitive spectrophotometry is proposed for the determination of trace cobalt based on Co(Ⅱ) catalysed decoloring reaction of Litchi Chinenses red by sodium perborate under the condition of triethanolamine as an activator. The apparent molar absorptivity ε500 is 1.8 × 107 L. mol-1· cm-1. The equation of calibration curve is log with the linear range of 0 ~ 0 .4 μg/L (r = 0.9998), the detection limit is 1.0 × 10-13 g/mL. This catalytic decoloration is a first order reaction and its activation energy E is 42. 12 kJ/mol, rate constant k is 1. 60 ×10-3- s-1. The method has been applied to the determination of trace Co(Ⅱ) in serum and urine samples with satisfactory results.