人发中痕量汞的氢化物发生-原子荧光法测定

在常规和高温高湿环境下，采用氢化物发生-原子荧光法测定了人发中的痕量汞，研究了样品处理、仪器分析和快速消除不良记忆的方法。结果表明，在高温高湿环境下选择稍高的负高压并控制标准空白的荧光度，能缓和Hg的不稳定性对测量的影响，而标准曲线的线性、样品和标样的测量值与常规条件无显著差异。还原剂浓度以1.5%～2.5%为好，过高或过低时常有信号溢出或无信号现象，仪器的灵敏度和稳定性不易平衡。H₂SO₄残留导致样品空白的荧光度高于标准空白，在高温高湿环境下尤为明显，故样品处理时慎用H₂SO₄。负高压校正和优化线性校正能快速消除不良记忆对测量的影响。该方法快速、准确，精密度≤1.1%，检出限为0.006 ng·mL-1。

Determination of Trace Mercury in Hair by Hydride Generation Atomic Fluorescence Spectrometry

A method for determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry under normal or high temperature and high humidity condition was described. The ways of samples pretreatment, analysis and rapid clearing up bad memory were researched. The results showed: that the effect of instability of mercury can be cushioned under high temperature and high humidity condition by choosing much negative high pressure and control long the fluorescence intensity of standard blank. There weren’t evident differences in the measure results of standard graph, standard and sample between normal and high temperature and high humidity conditions. When the reducer concentration was more than 2.5 percent or less than 1.5 percent the fluorescence signal was often overrun or disappeared. The sensitivity and stability of instrument weren’t easily balanced. Due to sulfuric acid remainder, the fluorescence intensity of sample blank was higher than that of standard blank, especially under high temperature and high humidity, so in the proceed of sample pretreatment sulfuric acid was used scarcely. The bad memory effect can be cleared up rapidly by correction of negative high pressure and correction of oftimized standard graph. The method was rapid and accurate. The relative standard deviation (RSD) was equal to or small than 1.1%. The detection limit of the method was 0.006 ng·mL-1.