基体改进剂在《GB 5009.12-2010食品中铅的测定》中的应用

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

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。

The matrix modification effect of NiNO3 on microgram amounts of Ph in food by graphite furnace atomic adsorption spectrometry was studied. The experimental results suggested that the addition of 200 mg/L NiNO3 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 10μ g/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.