催化动力学法测定化探样品中的痕量铬

Catalytic Kinetic Determination of TraceChromium in Geochemistry Samples

本文对在弱酸性介质中铬（Ⅵ）强烈催化Ｈ＿２Ｏ＿２氧化铬蓝黑Ｒ褪色反应进行了一系列研究，拟定了用催化动力学法测定铬（Ⅵ）的最佳条件。该法检出限为３．２×１０￣＿（－９）ｍＬ，测定线性范围０～１．５μｇ／２５ｍＬ铬（Ⅵ），用于化探样品中痕量铬的测定，结果良好。

Chromium can catalyze the decolorization oxida-tion of chrome blue-black R by H_2O_2 in weak acidmedium.The conditions of kinetics have been studiedin detail and the optimum conditions of catalytic kinet-ic determination of chromium were established. Thedetection limit of chromium in this method is 3.2×10￣(-9)g/mL and the linear response is in the range of 0～1. 5μg/25mL chromium. Satisfactory results wereobtained for the determination of trace chromium ingeochemistry samples.