食品中铅的红外消解-氢化物发生-原子吸收光谱测定法

Determination of Lead in Food by Infrared Digestion-Hydride Generation-Atomic Absorption Spectrometry

目的建立食品中铅的红外消解-氢化物发生-原子吸收光谱测定法。方法以盐酸-铁氰化钾-硼氢化钾反应体系,将铅氧化为Pb4+,导入电热石英原子化器,采用高性能空心阴极灯作光源,进行原子吸收光谱检测。结果该方法的检出限为0.070μg/L,线性范围为0～16μg/L,相关系数为0.9995,标准溶液的RSD小于1.92%,样品溶液的RSD小于3%,平均加标回收率为97%。结论该方法操作简便,试验成本低,适于基层卫生检测机构对食品中微量铅的常规检测。

Objective To develop a simple test method to determine lead in the food by atomic absorption spectrometry. Methods Based on the system of HCl-K3Fe(CN)6-KBH4, lead in the food samples was oxidized into Pb4+ and formed PbH4 in the continuous flow injection hydride generator and then the PbH4 vapour was put into atomization, the atomic absorption spectrometry was used to determine lead. Results The detection limit was 0.070 μg /L, the linear range of standard curve was 0-16 μg /L, the correlation coefficient (r) was 0.999 5, RSD was less than 1.92% for the standard solution, and less than 3% for food samples, average recovery rate was 97%. Conclusion This method is simple, low cost and applicable to the determination of trace lead in the food.