应用氢化物发生-原子荧光光谱法联合测定大米中砷和汞

HG-AFS DETERMINATION OF TRACE AMOUNTS OF ARSENIC AND MERCURY IN RICE

研究了应用氢化物发生-原子荧光光谱法联合测定大米中砷和汞,方法灵敏度高、准确度好。在最佳条件下,以50g/L硫脲+50g/L抗坏血酸为预还原剂,荧光强度与砷浓度在0.0512～200ng.mL-1范围内呈线性关系,检出限达0.0512ng.mL-1,荧光强度与汞浓度在0.0214～200ng.mL-1范围内呈线性关系,检出限达0.0214ng.mL-1;测定6个大米样品中砷汞,相对标准偏差:砷为2.1以下,汞为1.8以下;回收率:砷为91.6%-107.2%,汞为93.5%-108.7%。

The optimum conditions for the HG-AFS associated determination of arsenic and mercury were studied and an AFS method for tire determination of arsenic and mercury in rice is proposed. Sensibility is high and accuracy is good in this method. Under the conditions proposed, there is a linear relationship between the fluorescence intensity and arsenic conceutration in the rage of 0. 0512～200 ng？mL-1,and it＇ s detection limit is found to he 0.051 ng？mL-1 and the RSDs were under the rage of 2.1%; there is a linear relationship between the fluoreseence intensity and mercury concentration in the rage of 0.0214～200 ng？mL-1,and it＇ s detection limit is found to be 0.0214 ng？mL-1 and the RSDs were under the rage of 1.8%; the method was successfully applied to the determination of arsenic and mercury in six kinds of rices with a recovery range of 91.6%-107.2% and 93.5%-108.7%.