A simple and low-cost differential pulse-adsorptive cathodic stripping voltammetry (DP CSV) approach has been established for trace determination and speciation of Pb using Thorin-I as selective chelating agent. The established assay was based upon controlled preconcentration of Pb–Thorin complex at pH 8.3–9.0 at a hanging mercury dropping electrode (HMDE). The resulting cathodic peak current (I_p,c) at − 0.56 V was then measured versus Ag/AgCl reference electrode. The plot of I_p,c versus Pb concentration under the optimized parameters was linear in the concentration range 3.5 × 10^–10 − 5.0 × 10^–7 mol L⁻¹. The lower limits of detection (LOD) and quantification (LOQ) of Pb were 1.05 × 10^–10 and 3.5 × 10^–10 mol L⁻¹, respectively. The planned assay was satisfactorily applied for total analysis and speciation of Pb in various water and food samples. Validation of the developed probe was successfully achieved by analysis of Pb in certified reference material.

已经建立了一种简单且低成本的差分脉冲吸附阴极溶出伏安法（DP CSV），用于使用Thorin-I作为选择性螯合剂进行痕量测定和铅的形态分析。既定的测定是基于悬挂式汞滴电极（HMDE）在pH 8.3-9.0下Pb-Thorin复合物的可控预浓缩。然后，相对于Ag / AgCl参比电极，测量了在-0.56 V时产生的阴极峰值电流（I _p，c）。在优化的参数下，I _p，c对Pb浓度的曲线在浓度范围3.5×10 ^–10 − 5.0×10 ^–7  mol L ^-1内呈线性关系。铅的检测下限（LOD）和定量下限（LOQ）分别为1.05×10 ^–10和3.5×10 ^–10  mol L ^-1。计划的分析可令人满意地用于各种水和食物样品中铅的总分析和形态分析。通过对认证参考物质中的Pb进行分析，成功完成了对开发的探针的验证。