石墨炉原子吸收法测定食品铅技术的探讨

Determination of lead in food by GFAAS

目的：建立石墨炉原子吸收法测定食品铅的新技术。方法：采用硝酸＋硫酸＋双氧水消解样品,再用氢碘酸还原剩余硫酸;选用磷酸二氢铵（2%）＋氯化钯（0.4%）作基体改进剂,提高灰化温度,有效去除基体干扰,在选定的仪器条件下测定食品中铅。结果：铅在3～120μg/L范围内线性良好,方法定量限为0.0028 mg/kg,加标回收率为90.3%～107%,相对标准偏差（RSD）为1.2%～7.5%。结论：本法简便、快速、准确,灵敏度及精密度高,适用于食品中铅的测定。

Objective：To develop a method for the determination of lead in food by GFAAS.Methods：The samples were digested by a mixture of nitric acid,sulfuric acid and hydrogen peroxide and then the hydrogen periodate restored the remaining sulfuric acid.Ammonium dihydrogen phosphate（2%） and PdCI2（0.4%）,as a matrix modifier,can improve cineration temperature and effectively remove matrix interference.Results：The linear range was 3~120 μg/L,quantification limit was 0.0028 mg/kg,recoveries were 90.3%~107% with the relative standard deviation（RSD） of 1.2%~7.5% for the method.Conclusion：The method was simple,rapid,accurate and sensitive.It has been successfully applied to determination of lead of in food.