原子荧光法测试汞的漂移对策及标准空白过高的探讨

Discussion on Signal Drift Countermeasure and Study on High Standard Blank Problems

针对原子荧光法测试汞的信号漂移问题,分析了信号稳定时间长的原因,列举了空心阴极灯质量、仪器管路与原子化器污染等引发的信号漂移表现形式,提出了消除信号漂移对策,以及一种简单的仪器预热方法和直观的稳定性判定方法。笔者在用原子荧光法测定汞时,遇到多次标准空白过高的情况,由于标准空白过高导致校准曲线的线性比较差,直接影响到实验结果。选用不同厂商的聚丙烯和玻璃比色管,研究了比色管材质对汞分析结果的影响。结果表明,聚丙烯材质加热时会释放含量差异悬殊的汞,不宜直接用于低汞样品测试。

For the signal drift in determination of mercury by atomic fluorescence spectrometry(AFS),the reason of longer time for signal stability was discussed.Drift performance characteristic which was caused by quality of hollow cath-ode lamp and pollution of instrument pipe and atomizer,and train of thought for elimination was respectively illustrated.A simple instrument preheating method and an intuitive stability discriminated method were provided.On account of no speci-fied comparison tube material in determination mercury related standard,the effect of polypropylene and glass tube compari-son on the analysis result of mercury was studied.The experimental results showed that the disparity mercury was releasedfor heating polypropylene,which was not suitable for direct analysis of the sample with low content mercury.