阻抑动力学光度法测定绞股蓝中痕量钴

INHIBITORY-KINETIC PHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF COBALT IN GYNOSTEMMA PENTAPHYLLUM

基于钴(Ⅱ)在稀硫酸介质中对乙二胺四乙酸活化重铬酸钾氧化丁基罗丹明B的阻抑反应,建立了阻抑动力学光度法测定痕量钴(Ⅱ)的方法.检出限为2.65×10-6g·L-1,线性范围为0～0.60μg/25 mL,RSD＜4%,平均回收率为98.5%,应用于实际样品中痕量钴的测定.

The inhibitory action of traces of Co（ Ⅱ ） ion on the oxidation-decoloration reaction between butyl rhodamine B and Potassium dichromate catalyzed by EDTA in a dilute sulfuric acid medium was studied and adopted as a method for the determination of trace amounts of cobalt in gynostemma pentaphyllum, The limit of detection of the method is 2. 65×10^-6g · L^-1 , and the linearity range is 0 to 0. 60 μg of Co（ Ⅱ ） per 25 mL of solution. The RSD＇s （n=7） obtained in its application to the analysis of 4 gynostemma pentaphyllum samples was less than 4%, and the average recovery found by standard addition method was 98. 5%.