一阶导数停流法测定药物和饮用水中的铁

本文利用Ｆｅ＾３＋离子催化Ｈ２Ｏ２氧化四甲基对苯二胺的反应，将采用停流技术获得的动力学曲线转换成一阶导数曲线，根据导数峰高值与Ｆｅ＾３＋离子浓度的线性关系测定药物和自来水中的含量，本方法的线性范围为４．０－４０．０ｎｇＦｅ＾３＋／ｍｌ，相对标准偏差小于２．５％，标准加入回收率在９８．７％－１０１％之间，检测限为１．９２ｎｇＦｅ＾３＋／ｍｌ。对照实验结果表明，导数动力学法比一般非导数动力学法具有线关

Determination of Iron in Drinking Water and Medicine by First Derivative Stop-flow Method

A first derivative stop-flow method is described for the determination of iron in medicine and drinking water, based on its catalytic effect on the oxidation of tetramethyl-p-phenylenediamine by H_2O_2. After the kinetic curve is transformed into the first derivative curve, the content of iron in medicine or drinking water can be determined according to the linear relationship between the peak value and iron concentration. The linear range of determination is 4. 0-40. 0 ng Fe~(3+)/ml. The relative standard deviation is less than 2. 5%, and the recovery is from 98. 7% to 101%. The detection limit is 1. 92 ng Fe~(3+)/m1. The results of comparative test show that the derivative kinetic method has some advantages such as good linear relationship, low detection limit and short analysis time.