原子荧光光谱法同时测定粮食中砷汞总量的条件选择及干扰控制

Selection of Working Conditions and Interference Control for Simultaneous Trace Analysis the Content of As and Hg in Grain by AFS

通过优化原子荧光光谱仪的原子化高度、负高压、灯电流和载气流量等4个主要工作条件,并对仪器产生干扰的因素环境温度、光源稳定性、试剂进行研究,并用加标回收实验对方法的准确度进行验证,确定了原子荧光光谱法同时测定粮食中砷汞总量时的最优条件和有效的干扰控制方法。结果显示,在最优条件下,As的检出限为0.0247ng/mL,相对标准偏差(RSD)为0.37%,线性相关系数r=0.9999;Hg检出限为0.0015ng/mL,相对标准偏差(RSD)为0.44%,线性相关系数r=0.9999,仪器检测稳定性好,灵敏度高,各项指标均优于标准规定,且检测结果精密度高、准确性好。

The stability and sensitivity of AFS with working conditions such as atomization height,negative high voltage,lamp current and carrier gas flow rate were investigated and optimized.The interference factors,such as ambient temperature,light source stability and reagent were studied,the accuracy of the experiment was carried out by recovery experiments,the optimum conditions and effective interference control methods for simultaneous determination of arsenic and mercury in grain by atomic fluorescence spectrometry were determined.The results show that under the optimum conditions,the detection limit of As is 0.024 7 ng/mL,the relative standard deviation(RSD)was 0.37%,the linear correlation coefficient r=0.999 9;the detection limit of Hg was 0.001 5 ng/mL,the relative standard deviation(RSD)was 0.44%,and the linear correlation coefficient r=0.999 9.The instrumentation has good stability,high sensitivity,and each index was superior to the standard,and the test results had better precision and accuracy.