微波消解-石墨炉原子吸收光谱法测定土壤中铅和镉

Determination of Lead and Cadmium in Soil by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry

[目的]建立微波消解-石墨炉原子吸收光谱测定土壤中铅和镉的分析方法。[方法]土壤样品研磨过100目筛,用硝酸-氢氟酸-过氧化氢混合消解液微波消解后,石墨炉原子吸收光谱测定。[结果]铅浓度为5.0~40.0μg/L、镉浓度为0.20~2.00μg/L时,石墨炉原子吸收光谱测定土壤中铅和镉的方法线性良好,相关系数均为0.9999。铅和镉的方法定量检出限分别为5.0、0.040mg/kg。加标回收率为90.0%~110.0%,相对标准偏差为4.1%~6.9%,标样的测定结果在不确定度范围内。[结论]该方法简便、快速,基体干扰少,结果准确,适用于土壤中铅、镉含量的测定。

[Objective] To establish a method to measure lead and cadmium in soil by microwave digestion-graphite furnace atomic absorption spectrometry（FGAAS）.[Methods]Soil samples were ground to pass 100-mesh sieve,digested using HNO3-HF-H2O2 under microwave treatment and determined by GFAAS.[Results]When the lead concentrations were in the range of 5.0-40.0μg/L and the cadmium concentrations were in the range of 0.20-2.00μg/L,the linearity of this method was good,with a correlation coefficient of 0.9999.The detection limits of lead and cadmium were 5.0 and 0.040mg/kg respectively.The recovery rate was 90.0%-110.0%.The relative standard deviation was 4.1%-6.9%.The determination results of standard samples were within the uncertainty.[Conclusion]The method is characterized by simple,rapid,and little disturbance with high accuracy;therefore,it is suitable for regular measurement of lead and cadmium in soil.