热分解-冷原子吸收法测定土壤中汞

采用热分解处理土壤样品,用冷原子吸收法测定样品中的汞,通过优化固体测汞仪的分析条件、确定校准曲线的线性范围和样品的称样量,使该方法在0.025 mg/kg~1.50 mg/kg范围内线性良好。当取样量为0.2 g时,方法检出限为0.000 9 mg/kg,有证标准物质的测定结果在保证值范围内,高、低浓度标准物质6次测定结果的RSD分别为4.6%和4.8%。用热分解法与国标法同时处理样品并测定,其测定结果无显著差别。

Determination of Mercury in Soil by Thermal Decomposition Cold Atomic Absorption Spectrometry

The method of thermal decomposition cold vapor atomic absorption spectrometry for determination of mercury in soil was studied. By optimizing the instrument parameters of mercury analyzer, detecting the linear range of the calibration curve and sampling weights, it concluded that the calibration curve had a good linear range from 0.025 mg/kg~1.50 mg/kg. The detection limit was 0.000 9 mg/kg with 0.2 g sampling weights. The results of two standard samples were within the uncertainty of its guaranteed values, and the relative standard deviations were 4.6% and 4.8%, respectively. Comparing this method with national standard method, no significant difference was detected in measuring results.