提出了应用原子荧光光谱法测定土壤中砷和锑的含量.取一定量的试样于聚四氟乙烯消化罐中,加入盐酸-硝酸-水(3+1+4)混合酸于室温处理30 min,随后移入微波消解仪中按预设程序消解.于所得试液中加入一定量的硫脲-抗坏血酸混合溶液后加水定容为10.0 mL,分取上层澄清试液2 mL,注入于反应器中使其与还原剂(硼氢化钾溶液)反应.所生成的砷和锑的氢化物由氩气带入至石英原子化器中.文中详细给出了AFS仪器的工作条件,经试验求得砷及锑两元素的检出限(3S/N)均为0.050 μg·L-1.在已知砷、锑量土壤试样的基础上,加入3个浓度水平的砷和锑的标准溶液后,按所提出的方法作回收试验,根据结果算得砷及锑的回收率依次在99.5%~104.0%及98.5%~99.5%之间.

AFS was applied to the determination of arsenic and antimony in soil.The sample was first treated with a mixed acid of HCl+HNO3+H2O (3+1+4) for 30 min at room temperature and then digested in the microwave digestor under the prescribed program.A mixed solution of thiourea and ascorbic acid was added to the sample solution which was used for AFS determination after diluting to 10.0 mL.A aliquot of 2 mL of the supernatant sample solution was injected into the reactor to react with the reductant (KBH4 solution) and the hydrides of arsenic and antimony were carried over into the quartz atomizer by argon.Details of working condition of the AFS instrument were given.Values of detection limit (3S/N) for both As and Sb were found same as 0.050 μg·L-1.Recovery of the method was tested at 3 concentration levels by adding standard solutions of As and Sb to a soil sample as matrix,values of recovery found were in the ranges of 99.5% to 104.0% (for As) and 98.5% to 99.5% (for Sb).