高压密闭消解土壤砷、汞、铅、镉酸体系比较

采用高压密闭消解系统消解土壤,氢化物发生-原子荧光光谱法(HG-AFS)测定As和Hg,石墨炉原子吸收光度法(GF-AAS)测定Pb和Cd,对比了不同消解酸体系对国家土壤标准参考样中As、Hg、Pb、Cd的消解效果。结果表明,盐酸-硝酸体系对As、Hg、Pb和Cd的消解平均回收率分别为26.1%、100.6%、69.7%、87.3%;硝酸-高氯酸-氢氟酸体系中As、Hg、Pb和Cd消解平均回收率分别为109.9%、84.7%、87.5%、90.1%;硝酸-双氧水体系对Hg、Pb、Cd消解平均回收率分别为104.8%、95.1%、93.3%,对As的回收率虽只有69.2%,但数据精密度最好。此外,从简化试验步骤,减少误差,提高检测效率及减少试验危险性等方面综合评价,认为硝酸-双氧水消解体系是采用高压密闭系统消解土壤重金属的最理想酸体系。

Comparison of Different Acid Systems in the Procedure of Digestion and Decomposition of Soil Arsenic,Mercury,Lead and Cadmium Using High Pressure Method

Standard soil samples were digested in high pressure vessels by different acid systems to measure the concentrations of Arsenic(As),Mercury(Hg),Lead(Pb) and Cadmium(Cd).As and Hg were determined with HG-AFS,and Pb and Cd were measured with GF-AAS.The results showed that the average recoveries of As,Hg,Pb and Cd were 26.1%,100.6%,69.7%,87.3%;109.9%,84.7%,87.5%,90.1%;69.2%,104.8%,95.1%,93.3% with acid systems of HCl-HNO_3,HNO_3-HClO_3-HF and HNO_3-H_2O_2 respectively.The accuracy and precision of HNO_3-H_2O_2...