微波消解-GFAAS法测定小麦粉中铅的含量

本文应用微波消解-石墨炉原子吸收光谱法对小麦粉中铅的含量进行测定。小麦粉经HNO_3+H_2O_2微波消解体系消解后,采用硝酸钯和磷酸二氢铵作为化学改进剂,将灰化温度提高到1100℃,从而大大降低基体的干扰。铅的含量在0～20ng/mL范围内呈线性关系,线性相关系数为0.9953;本法检出限为1.8ng/mL,RSD小于3%,回收率在90%～110%之间。结果表明,该方法操作简便、易行,样品中铅损失少,测定结果重现性好,准确度高,具有很强的实用性。

Determination of lead content in wheat powder by GFAAS with microwave digestion

A method of atomic absorption spectrometry with microwave digestion was applied to determination of lead content in wheat powder.The samples were digested by closed-vessel microwave HN03+H2O2 diges.and decline background absorption sharply.The calibration curve was linear over the concentration ranges of O～20ng/mL with the correlation coefficient of O.9953.The detection limit was 1.8ng/mL,and the relative standard deviations(RSD)were no more than 3%.Recovery of spiked samples was 90%～1100%.These results showed the method is simple,convenient and the analytical data meet the demands of repeatability and accuracy.