净水技术2025，Vol.44Issue(9)：196-205,10.DOI:10.15890/j.cnki.jsjs.2025.09.024
共沉淀原子吸收石墨炉法测定食用盐中的镉含量
Determination of Cadmium Content in Edible Salt by Method of Co-Precipitation Atomic Absorption Graphite Furnace
摘要
Abstract
[Objective]Addressing the issues of severe matrix interference from sodium chloride(with a recovery rate of only 30%to 50%)and significant detection errors in the direct determination of cadmium content in edible salt using the graphite furnace method of atomic absorption spectrophotometry,this paper proposed an innovative method based on co-precipitation for enriching cadmium ions while reducing matrix interference.[Methods]Leveraging the characteristic that cadmium ions could form cadmium hydroxide under alkaline conditions,iron nitrate was introduced as a co-precipitant.The pH of the sample solution was adjusted to 9.0 with ammonia water,enabling the formation of stable precipitates of cadmium hydroxide and iron hydroxide through co-precipitation.The supernatant containing high concentrations of sodium chloride was carefully aspirated,and the precipitate was acidified and dissolved for determination using the graphite furnace method of atomic absorption spectrophotometry.[Methods]Validation was also conducted using inductively coupled plasma mass spectrometry(ICP-MS).[Results]The improved method significantly increased the recovery rate to 104%,with a relative standard deviation of 2.4%.Furthermore,the relative standard deviation with ICP-MS measurement result was only 0.03%.[Conclusion]This method eliminates the interference from sodium chloride in the sample through the co-precipitation process,while achieving enrichment of cadmium elements,significantly lowering the detection limit of the experiment,and improving the accuracy of determination.This study also provides an efficient solution for the precise detection of trace heavy metals in high-salt matrix samples,significantly enhancing detection sensitivity,accuracy,and precision.关键词
食用盐/原子吸收石墨炉法/共沉淀法/镉含量/痕量测定/硝酸铁Key words
edible salt/atomic absorption graphite furnace method/co-precipitation method/cadmium content/trace determination分类
资源环境引用本文复制引用
房合书,周民兰,杨帆,丁梅,彭昌龙,黄于富..共沉淀原子吸收石墨炉法测定食用盐中的镉含量[J].净水技术,2025,44(9):196-205,10.基金项目
2024年度无研发活动规上工业企业扶持计划项目:食用盐中镉含量的测定方法改进[黔科统研[2024]344号] （）
