基体改进剂在《GB 5009.12-2010食品中铅的测定》中的应用

探讨了硝酸镍对石墨炉吸收法测定食品中铅的基体改进作用。实验表明:在200mg/L硝酸镍的基体改进剂存在下,仪器信号灵敏度提高3倍;在最佳测试条件下,铅特征质量为4.1pg/0.0044A,检出限为0.001mg/kg;12.5ng/mL铅标准溶液11次测定的RSD为1.2%;10μg/mL的Ca、Cd、Cr、Cu、Fe、K、Zn、Mg、Mn和Sn对12.5ng/mL铅标准溶液的测定无干扰作用。该法克服了国家标准《GB 5009.12-2010食品中铅的测定》第一法石墨炉原子吸收光谱法信号灵敏度低、稳定性差、重复性低等缺点。

Application of Matrix Modifier in 《GB 5009.12-2010 Determination of Lead in Food》

The matrix modification effect of NiNO_3 on microgram amounts of Pb in food by graphite furnace atomic adsorption spectrometry was studied.The experimental results suggested that the addition of 200 mg/L NiNO_3 resulted in 3 fold increase in sensitivity.Under optimum conditions,a characteristic mass of 4.1 pg/0.0044A and a detection limit of 0.001 mg/kg were obtained.Eleven tests of a 12.5 ng/mL Pb standard solution gave a RSD of 1.2%.For the 12.5 ng/mL Pb standard solution 10μg/mL of Ca、Cd、Cr, Cu、Fe、K、Zn、Mg、Mn and Sn caused no significant interference.The developed method has improved the limitation such as weak sensitivity,bad stability and repetition of the 1~(st)method in national food safety standard《GB 5009.12-2010 determination of lead in food》by graphite furnace atomic adsorption spectrometry.