电感耦合等离子体发射光谱粉末进样法测定粮食及茶叶中微量元素的研究

Determination of Trace Elements in Cereals and Tea Leaves by Inductively Coupled Plasma-Atomic Emission Spectrometry With Powdered Sample Introduction System

本文探讨了 ICP-AES 粉末法分析大米,小麦及茶叶中微量元素的条件。试样的基体成分不同,但用粉末进样器和封闭式 ICP-arc 双放电装置,在选定的条件下,只用淀粉基体的标准即可进行分析。并用空间温度分布及抑制粒度效应等数据说明其合理性.

The characteristics of an inductively couplid plasma incorporated with a powder sample introduction device and two enclosed electrodes to generate an arc at a distance abo- ve the induction coil have been studied.It is found that by decreasing the rate of sample introduction from 1.4 to 0.4 mg/s an enhancement of the intensities of the analyte lines is attiained.At the low sampling rate and with the auxiliary are discharge the observation height with line-intensities maximum and excitation temperature moves upward to 13～15mm, which is usually 8～10 mm for powdered samples when the are is not applied.This raise in optimum observation height is benificial to improving the efficiency of sample vaporizat- ion and atomization.For different samples,no significant change in excitation temperature is found at the low sampling rate and at the optimum observation height when the auxiliary are is applied,so one single set of synthetic standards can be used to determine several elements in rice flour,wheat flour,and tea leaves,respectively.