固相萃取柱脱盐-石墨炉原子吸收法测定酱油中铅

目的 建立固相萃取柱脱盐—石墨炉原子吸收法测定酱油中铅的方法.方法 酱油经微波消解后,消解液用乙酸铵调节至pH≈5.5,过经用5 ml 1 mol/L乙酸铵活化后的DigiSEP-Blue柱,将被测元素铅吸附与基体中高盐分离,再分别用8 ml 2 mol/L硝酸、2 ml纯水洗脱,应用石墨炉原子吸收法测定洗脱液中铅含量.结果 用固相萃取柱可将酱油中98％以上的钠盐与被测元素铅分离,消除了石墨炉原子吸收分光光度计测定铅时的基体干扰.低、高两个铅浓度(10和30 ng/ml)的加标平均回收率(n=7)分别为91.3％ ～95.1％,97.9％～98.6％,相对标准偏差为2.1％ ～7.0％,检出限为1.33 ng/g.结论方法准确、灵敏度高,适于高盐样品酱油中铅含量的测定.

Desalting with solid phase extraction cartridge and using GF-AAS for the determination of lead in soy sauce

Objective To establish a solid phase extraction(SPE) with atom absorption spectrometry(AAS) for the determination of lead in soy sauce samples.Methods The samples were pretreated by microwave digestion.After the digested solution being adjusted to pH 5.5 by ammonium acetate,the solution was then passed through a DigiSEP-Blue cartridge pretreated by 5 ml of 1 mol/L ammonium acetate for the removal of large amount of salt.The eluate from the DigiSEP-Blue cartridge washed by 8ml of 2 mol/L nitric acid and 2 ml...