大米中砷和汞的微波消解-原子荧光光谱测定法

Determination of arsenic and mercury in the rice by microwave digestion-atomic fluorescence spectrometry

目的建立双道原子荧光光谱法同时测定大米中的砷和汞的方法。方法采用微波消解法处理大米样品,以原子荧光光谱法同时测定其中的砷和汞。结果砷和汞的检出限分别为0.004 4、0.039μg/L;砷、汞标准溶液分别在1.0～20.0和0.10～1.20μg/L范围内线性良好,其相关系数分别为0.999 5、0.999 2;精密度RSD:测定含2.0μg/L砷和0.4μg/L汞的混合标准溶液的RSD分别为2.12%、4.59%。样品加标回收率:砷92.2%～96.8%,汞90.3%～92.1%。结论该方法灵敏度、准确度高,操作方便快速,具有较低的检出限,能满足同时测定大米中砷和汞含量的测定工作。

[Objective]To establish the method for simultaneous determination of trace arsenic and mercury in rice by dual-channel atomic fluorescence spectrometry.[Methods]The rice samples was digested by microwave,then the trace arsenic and mercury were simultaneously determined by Atomic fluorescence spectrometry.[Results]The detection limits were 0.004 4 μg/L for arsenic and 0.039 μg/L for mercury;there was a linear relationship between 1.0-20.0 μg/L of arsenic standard solution,0.10-1.20 μg/L of mercury standard solution.The correlation coefficients were 0.999 5 for arsenic and 0.999 2 for mercury.The precision RSD was 2.12% for 2.0 μg/L arsenic mixed standard solution,and 4.59% for 0.4 μg/L mercury mixed standard solution.The recoveries were 92.2%-96.8% for arsenic and 90.3%-92.1% for mercury.[Conclusion]This method is very sensitive,with high accuracy,easy and fast.It has lower detecting limit,and can determine the content of Arsenic and Mercury in rice simultaneously