炉内消解-石墨炉原子吸收法快速测定液态保健食品中铅含量

摘要

目的 建立直接进样,利用石墨炉高温消解样品并测定样品中铅含量的方法.方法 样品不经微波消解炉消解,稀释后直接进样,利用石墨炉可程序升温的特性,通过改变升温程序和添加基体改进剂,减少样品基体对测定结果的影响,直接测定样品中铅含量.结果 8 h内测定样品的相对标准偏差(RSD)均小于5%(n=5);检出限为0.14μg/L;回收率在80%~105%之间.结论 本方法操作简便,结果准确可靠,可用于液态保健食品中铅含量的快速测定.%Objective To establish a method for determination of lead in liquid health food by graphite furnace atomic absorption spectrometry (GF-AAS) with furnace- digestion. Methods The contents of lead in samples were directly determined by GF-AAS. The digestion of the samples were accomplished in the graphite furnace after dilution, rather than in microwave oven beforehand. In order to reduce the matrix interference, the temperature program of the graphite furnace was altered, and modifier solution was added. Results The relative standard deviation (RSD) of this method was less than 5 % (in 8 h, n=5). The detection limit was 0.14 μg/L, and the recoveries were 80 %-105 %. Conclusion This method has advantage of convenient manipulation, time-saving, high accuracy and reliability. It can be applied in lead determination of liquid health food.