场地污染土壤中总汞的分析方法

Analytical Method of Total Mercury in Contaminated Soils Using Atomic Fluorescence Spectrophotometer

建立污染土壤中总汞分析的前处理和分析测试方法。以标准土样(GBW07405-GSS5)为供试土壤,从样品量、消解液体积、消解时间、不同分析仪器效果方面优化分析测试条件。结果表明,土壤样品前处理条件为,0.5g土壤样品中加入1∶1王水8mL,冷消解18h后,沸水浴消解1h;分析测试条件为,原子分光光度计(AFS-3000)的光电倍增光负高压280V,灯电流25mA。本法总汞的检出限为0.005μg/L,相对标准偏差为2.7%,回收率为94.4%～107%。用某化工厂含汞盐泥堆存场地附近、某电石法聚氯乙烯生产车间周边、某曾经进行过汞法烧碱的车间周边污染土壤进行方法验证,相对标准偏差为0.24%～0.98%,结果没有显著性差异。方法重现性好,分析结果准确、可靠。

The preparation treatment and the measurement method were developed to determine the total mercury in contaminated soils. The standard soil （GBW07405-GSSS） was used, and different parameters were tried and selected including the quantity of the soil, digestion solution volume, digestion time, and analytical instruments. The selected preparation parameters were as follows. 8 mL of 1 ：1 aqua regia solution, 0.5 g soil samples, 18 h digestion in room temperature, and then digestion 60 rain in the boiled water bath. The atomic spectrophotometer （AFS-3000） was used to determine the mercury in the digestion solutions. The detection limit of total mercury was 0. 005 μg/L, relative standard deviation was 2.7%, the recovery ranged from 94.4 % to 107%. The total mercury of Hgcontaminated soils from different contaminated sites were analyzed using this measurement method, the relative standard deviation ranged from 0. 24% to 0.98%, and the statistical results showed that there was no significance among triplicate samples, indicating the method could provide reliable and accurate data.