全自动石墨加热消解-FAAS法测定土壤中的铅

Determination of Lead in Soil with Automatic Graphite Digestion Instrument by FAAS

[目的]为了建立测定土壤中的铅含量的全自动石墨消解-FAAS法。[方法]利用盐酸-硝酸-氢氟酸-高氯酸作为消解液,经全自动石墨加热消解,KI-MIBK萃取,采用火焰原子吸收光谱法测定土壤样品中的铅含量。[结果]铅（0.2～1.0 mg/L）的吸光度与浓度线性关系较好,r为0.999 5,检出限为0.18 mg/kg,回收率为97.8%～103.2%,RSD为2.68%～3.88%。[结论]该方法检测效率高,操作简便,准确性好,是测定土壤中铅含量的理想方法。

[Objective] The research aimed to establish a method with automatic graphite digestion instrument by using flame atomic absorption spectrophotometry（ FAAS） for the determination of lead in soil. [Method]Using hydrochloric acid-nitric acid-hydrofluoric acid-perchloric acid as remove fluid,the soil samples were digested by automatic graphite digestion instrument,then the lead content in the soil was detected by KI-MIBK extraction automatic graphite digestion instrument. [Result] The linear relationship between values of absorbance and mass concentration of lead was kept in ranges of 0. 2- 1. 0 mg / L,amd r was 0. 999 5 with the detection limit of 0. 18 mg / kg. The recovery rate obtained by standard addition method was in the range of 97. 8%- 103. 2% with RSD of 2. 68%- 3. 88%. [Conclusion] The method is simple,rapid and accurate,which is an ideal method for the determination of lead contents in the soil.