微波消解-石墨炉原子吸收法测定小海鲜产品中的铅和镉

Determination of lead and cadmium in seafood by GFAAS with microwave digestion

目的:建立小海鲜产品中铅和镉的微波消解-石墨炉原子吸收光谱测定方法。方法:以磷酸二氢铵-硝酸镁作基体改进剂,采用硝酸进行微波消解,利用塞曼扣背景,石墨炉原子吸收法测定小海鲜产品中的铅和镉含量。结果:铅和镉分别在2.0μg/L～50.0μg/L和0.2μg/L～5.0μg/L范围内具有良好的线性,相关系数大于0.999,铅镉的的最低检出限为5.4μg/kg湿重和0.31μg/kg湿重,加标回收率为90.0%～102.0%,RSD均小于5.0%,采用本法对国家标准物质贻贝GBW08571进行测定,经t检验(P>0.05),测定结果与标准值无显著性差异。结论:建立的方法具有简便、灵敏、准确的特点,适合于高盐海产品中铅镉的测定。

Objective：To establish a method for determination of lead and cadmium in seafood by graphite fumace atomic absorption spectrometry with microwave digestion.Methods： The seafood samples were digested with HNO3.The sample was analyzed by Zeeman GFAAS using NH4H2PO4–Mg（NO3）2 as matrix modifier.Results： The linear range of the method were 2.0 μg/L～50.0 μg/L for Pb,and 0.2 μg/L～5.0 μg/L for Cd with the correlation coefficients greater than 0.999.The limits of detection were 5.4 μg/kg wet weight for Pb and 0.31 μg/kg wet weight for Cd respectively.The recoveries were between 90.0%～102.0%,both RSDs were less than 5.0%.The accuracy and precision of the method were tested by the national standard substances（Mussels GBW08571）.There are no significant difference between the determined results and the given values.Conclusion： This method is simple,accurate and sensitive and suitable for determination of lead and cadmium in high salty seafood.