王水水浴消解-冷原子荧光法测定土壤和沉积物中的总汞

Determination of Total Mercury in Soil and Sediment by Aquaregia Digestion in the Water Bath Coupled with Cold Vapor Atom Fluorescence Spectrometry

土壤和沉积物中的总汞是环境监测的常规项目。不同消解方法对测定结果和分析进度影响较大。本文改进了与其它强氧化体系消解样品具有可对比性的传统王水消解法,利用王水在95℃水浴中一次消解,结合BrCl氧化-SnCl2还原-汞蒸汽吹脱金管预富集-冷原子荧光法测定了土壤和沉积物样品中的总汞。该方法操作简单,数据可靠,精度高,土壤和沉积物标准样品测定的相对误差为-4.6%-10.1%.回收率91.1%- 111.6%;平行样测定重现性良好,提高了分析速度和准确度。

Determination of total mercury in soils and sediments is common for the environmental monitoring. The analytical results and analytical speed are obviously affected by various digestion methods. The traditional aquaregia digestion method, which was comparable to other strong oxidation digestion methods, has been modified for analyzing total Hg in soils and sediments in this study. The adjusted procedure is as follow, soil and sediment samples were digested by aqua regia in the water bath at 95℃, then the solution was oxidized by BrCl, reduced by SnCl2 , then Hg vapor was purged through the bubbler and pre-collected in the gold trap and finally analyzed by cold vapor atom fluorescence spectrometry (CVAFS). It is proved that this modified technique is a simple and reliable method with high-accuracy for analyzing the total Hg in soils and sediments. Its relative error ranges from -4. 6% to 10. 1% and its recovery ranges from 91. 1 % to 111. 6%. This method will save the time and increase the precision for analyzing the total Hg in soils and sediments.