王水消解-冷原子吸收光谱法测定土壤中汞

为了寻求一种更加适宜测定土壤中汞含量的测试方法,将检出限低、精密度高的冷原子吸收光谱法与便捷、高效的王水水浴消解土壤处理方式相结合,建立了王水消解-冷原子吸收光谱法测定土壤中汞。通过测定方法的线性相关性、方法检出限、准确度、精密度、加标回收率,并与原子荧光光谱法进行对比实验来评价该方法的有效性。王水消解-冷原子吸收光谱法在汞质量浓度0.0～1.0μg/L范围内线性良好,相关系数可以达到0.999 9,方法检出限为0.000 75mg/kg,土壤标准样品测试的相对标准偏差为4.0%～10.7%,实际样品加标回收率分别为93%～104%。采用原子荧光光谱法进行对比测试,原子荧光光谱法的方法检出限为0.002 5 mg/kg,相对标准偏差为4.8%～13.5%,加标回收率为104%～107%。结果表明,对于王水水浴消解土壤的方法不仅适用于原子荧光光谱法测定汞含量,同样可以应用于冷原子吸收光谱法中。所建立的王水消解-冷原子吸收光谱法具有更低的检出限,更优的准确度和精密度,有利于提高土壤样品测试的工作效率,值得推广。

Determination of mercury in soil by cold atomic absorption spectrometry with aqua regia digestion

In order to find a more suitable test method for determination of mercury content in soil, cold atomic absorption spectrometry with low detection limit and high precision was combined with convenient and efficient aqua regia water bath digestion method to establish aqua regia digestion - cold atomic absorption spectrometry. To evaluate the effectiveness of the new method, the linear correlation, detection limit, accuracy, precision and standard recovery were determined,which was compared with atomic fluorescence spectrometry. Aqua regia digestion - cold atomic absorption spectrometry showed good linearity in the range of mercury mass concentration 0.0~1.0 g/L, and the detection limit of the method is 0.00075mg/kg, the relative standard deviation of soil standard sample test is 4.0%~10.7%, and the standard recovery of solid samples is 93%~104%, respectively. The detection limit of atomic fluorescence method was 0.0025 mg/kg, the relative standard deviation was 4.8%~13.5%, and the standard recovery was 104%~107%. The results showed that the method of dissolved soil in aqua regia bath was not only suitable for the determination of mercury content by atomic fluorescence method, but also suitable for cold atomic absorption method.The method has lower detection limit, better accuracy and precision, and is beneficial to improve the testing efficiency of soil samples, which is worth popularizing.