泡沫塑料富集–石墨炉原子吸收光谱法测定贝类水产品中痕量铊

Determination of Trace Thallium in Shellfi sh by GFAAS after Preconcentration with Foam Plastics

采取微波消解的前处理手段消解样品,经泡沫塑料分离富集后,用石墨炉原子吸收光谱法测定贝类水产品中痕量铊。以1.5 mL Fe3+,2 mL H2O2和5%王水介质作为吸附体系将样品中铊分离富集,再以硝酸钯、抗坏血酸作为基体改进剂进行测定。铊的质量浓度在0～50μg/L范围内线性良好,相关系数为0.999 7,方法的检出限可达0.07μg/g。测定结果的相对别准偏差为1.53%～4.01%(n=7),加标回收率为87.1%～98.3%。泡沫塑料富集–石墨炉子吸收光谱法测定贝类水产品中痕量铊是一种准确、安全、便捷的检测方法。

A method for the determination of trace thallium in shellfish by microwave-digestion-GFAAS was established after preconcentration with foam plastics. The trace thallium was adsorbed by foam plastics from 5%aqua regia medium in the presence of 1.5 mL Fe^3＋ion and 2 mL H2O2. Thallium was determined by GFAAS with ascorbic acid and Pd（NO3）2 as matrix modifier. The detection limit of the method for thallium was 0.07 μg/g. It had a good linearity when the contents of Tl in 0-50 μg/L, and the regression coefficient was 0.999 7. The relative standard deviation of determination results was 1.53%-4.01%（n=7）, and the recoveries for the spiked samples ranged from 87.1%to 98.3%. The method was suitable for determination of trace thallium in shellfish with the advantages of accuracy,safety and simplicity.