用硝酸铋共沉淀分离富集的火焰原子吸收法测定酱油中微量铅的方法研究

COPRECIPITATION SEPARATION AND PRECONCENTRATION WITH BISMUTH NITRATE FOR TRACE LEAD IN SOY SAUCE AND DETERMINATION OF LEAD BY FLAME ATOMIC ABSORPTION SPECTROMTRY

[目的]建立测定酱油中铅的火焰原子吸收法,为该类样品的准确定量提供可靠方法。[方法]对酱油样品经硝酸铋的共沉淀分离富集后用火焰原子吸收法进行测定。[结果]铅含量在0.045～1.60mg/kg呈线性关系,相关系数为0.9998,方法的检出限为0.013mg/kg,最低检出浓度为0.045mg/kg,相对标准偏差3.4%～5.4%,回收率为95.5%～103.0%。[结论]研究结果表明:该方法不仅具有操作简便、快速,同时又有良好的重复性、较高的回收率,能用于该类样品中铅的准确测定,对样品的测定结果与仲裁法一致。

[ Objective] To establish a method for determination of Lead in Soy Sauce by flame atomic absorption spec- trometry and provide the reliable method for accurate quantitative analysis of this kind of samples. [Methods] Flame atomic absorption spectrometry method was used to determine the samples of Soy Sauce which had been already separated and preconcentrated by coprecipitation with Bismuth Nitrate. [ Results] The linear range of the method was 0.045-1.60 mg/kg with a correlation coefficient of 0.999 8. The detection limit, the lowest quantitative limit, the relative standarded deviation and the recovery rate were 0.013 mg/kg, 0.045 mg/kg. 3.4-5.4% and 95.5-103.0% respectively. [ Conclusions] The results of research shows that the method had many advantages such as simplicity of operation, rapidity, better accuracy and higher recovery rate available for the accurate quantitative analysis of Lead in the samples.The results are consistent with those by arbitral method.