SPCE-微型DPSA-1仪同步快速检测蔬菜中的铅、镉、铜

Mini DPSA-1-SPCE for the Simultaneous Rapid Determination of Pb,Cd,Cu in Vegetables

以优化的微波消解法进行样品预处理,用微型DPSA-1仪结合丝网印刷碳电极,通过微分电位溶出法对蔬菜中的铅、镉、铜进行同步快速检测。结果表明,在1～840μg/L(相当于蔬菜中铅、镉、铜含量为0.0125～10.5mg/kg)范围内呈现良好的线性关系,铅的相关系数为r=0.9977,检出限为0.42μg/L(S/N=3);镉的相关系数为r=0.9976,检出限为0.34μg/L(S/N=3);铜的相关系数为r=0.9958,检出限为1.36μg/L(S/N=3)。研究了检测过程中存在多种干扰离子对于铅、镉、铜检测的干扰情况。试验检测26种蔬菜,所得检测结果与国标检测法进行t检验,无显著差异。与常规的检测技术相比,本法同步检测蔬菜中的铅、镉、铜具有更经济、简便、快速等优点,可实现样品的高比例筛检,还有望作为推广应用于其它类型食品和环境样品中铅、镉、铜快速检测的基础模型,具有很好的应用潜力和广阔的应用前景。

The aim of this work is to establish a better technology for rapid determination of Pb,Cd and Cu in vegetables at a synchronous pace.An optimized digestion method was developed to pre-treat the samples,differential potentiometric stripping analysis（DPSA） coupled to Mini DPSA-1 and screen-printed carbon electrode（SPCE） was employed as fast and sensitive electroanalytical method for heavy metals determination.The potentiometric stripping response for Pb,Cd and Cu under the optimized experimental parameters（Hg2 ＋ concentration of 3 × 10-4 mol /L,1.5mol /L pH 4.0 NH4 Cl as supporting electrolyte,deposition potential of-1.1V,final potential of-0.2V and deposition time 200 s） was linear over the concentration range examined（1 ～ 840 μg /L） with r values of 0.9977,0.9976 and 0.9966 and detection limit of 0.42,0.34 and 1.36 μg /L（S /N=3）,respectively.In addition,the study also focuses on the interference of certain ions in the procedure of detection.Twenty-six species of vegetables were detected by the rapid detection and by GB method.The comparison of these two sets of detection by t test indicated that the results were no significant differences.Compared with conventional detection technique,the present method was more convenient and cheaper.It could achieve a high percentage of sample screening and be applied to the simultaneous rapid detection of Pb,Cd and Cu in other food and environmental samples with a good potential application and broad prospects.