Solid phase extraction of trace cadmium and lead in food samples using modified peanut shell prior to determination by flame atomic absorption spectrometry
Solid phase extraction of trace cadmium and lead in food samples using modified peanut shell prior to determination by flame atomic absorption spectrometry
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DOI：
10.1007/s00604-008-0126-y
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发表时间：
2009-01
影响因子：
5.7
通讯作者：
G. Xiang;Yan Huang;Yifan Luo
中科院分区：
文献类型：
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作者：
G. Xiang;Yan Huang;Yifan Luo
用磷酸对花生壳进行化学修饰，将花生壳作为固相萃取材料，用火焰原子吸收光谱法测定食品样品中痕量Pb2+和Cd2+。考察了pH、样品流速和体积、洗脱流速和体积以及潜在干扰离子对分析物回收率的影响。结果表明，Pb2+和Cd2+在pH为6时可以吸附，用1.5 mL 0.1 mol L−1HCl洗脱。在优化条件下，改性花生壳对Pb2+和Cd2+的吸附量分别为116.7 mg g−1和37.5 mg g−1。Pb2+和Cd2+的检出限分别低至2.3和0.2 ng mL−1，理论浓度因子为40。茶叶标准样品（GBW07605）的分析结果与认证值吻合较好。该方法还适用于茶叶、白酒和奶粉中痕量Pb2+和Cd2+的测定，加标食品样品中Pb2+和Cd2+的回收率在90 ~ 114%之间。
Peanut shell was chemically modified with phosphoric acid and used as a solid phase extraction material for the determination of trace amounts of Pb2+and Cd2+in food samples by flame atomic absorption spectrometry. The effect of pH, sample flow rate and volume, elution flow rate and volume, and of potentially interfering ions on the recovery of the analytes were investigated. The results showed that Pb2+and Cd2+can be adsorbed at pH 6 and eluted with 1.5 mL of 0.1 mol L−1HCl. Under the optimized conditions, the adsorption capacity of modified peanut shell was found to be 116.7 mg g−1and 37.5 mg g−1for Pb2+and Cd2+, respectively. The limits of detection were as low as 2.3 and 0.2 ng mL−1for Pb2+and Cd2+, respectively, with a theoretical concentration factor of 40. The analytical results for the certified reference tea sample (GBW07605) were in a good agreement with the certified value. The method has also been applied to the determination of trace Pb2+and Cd2+in tea, liquor and milk powder, and the recovery of Pb2+and Cd2+for spiked food samples was between 90 and 114%.