碘化钾―甲基异丁基甲酮萃取―火焰原子吸收法测定土壤中的痕量铅

土壤样品经微波消解,在优化的条件下,用碘化钾―甲基异丁基甲酮萃取,采用火焰原子吸收光谱法测定其中的铅。结果表明,在盐酸质量分数为1%～2%,萃取时间为2 min,平衡时间为15 min,样品中的铅能被定量萃取。方法检出限为0.1 mg/kg。方法用于土壤标准样品测定,测定值与标准值相符,相对标准偏差为1.2%～1.4%,相对误差为0.8%～2.5%。实际土壤样品的测定结果显示,回收率为99.8%～100.4%。

Extraction of Lead in Soil with Potassium Iodide-Methyl Isobutyl Ketone and Determination by Flame Atomic Absorption Spectrometry

The soil sample digested by microwave digestion, extraction of lead with potassium iodide-methyl isobutyl ketone and determination by flame atomic absorption spectrometry. The results showed that lead could extract quantitatively at the concentration of hydrochloric acid was 1%~2% and extraction time was 2 min, equilibrium time was 15 min. The method detection limit was 0.1 mg/kg. The method has been applied to determination of standard soil samples; the analytical results were in accordance with the standard value. The relative standard deviation （RSD） was 1.2%~1.4%, the relative error was 0.8%~2.5%. The recovery of the practical samples was 99.8%~ 100.4%.