Monolayer-scale pyridine-2-sulfonic acid (PySA) or pyridine-2-carboxylic acid (PyCA) modified glassy carbon electrode (GCE) was prepared for anodic stripping voltammetry (ASV) analysis of Cd2+ and Pb2+. PySA or PyCA was covalently modified on GCE by electroreduction of PySA or PyCA in 0.5 M aqueous H2SO4, yielding a PySA/GCE or PyCA/GCE. The electrodes were characterized by X-ray photoelectron spectroscopy and electrochemical techniques. In combination with the in-situ bismuth film method, both PySA/GCE and PyCA/GCE offered very high analytical performance for ASV analysis of Cd2+ and Pb2+, including the very low values of limit of detection (LOD, S/N = 3) and high stability. The PySA/GCE gave a LOD of 4 ppt for Cd2+ or of 7 ppt for Pb2+. The PyCA/GCE gave a LOD of 7 ppt for Cd2+ or of 11 ppt for Pb2+. The Cu2+ and Ni2+ interferences, which still appear as a challenge for ASV analysis of Cd2+ and Pb2+, were found to be well inhibited by the additions of K4Fe(CN)6 and Ga(III) into the detection solution. The modified electrode was used for Cd2+ and Pb2+ analysis in real water samples with satisfactory results.

中文翻译：

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用于 Cd2+ 和 Pb2+ 阳极溶出伏安法分析的吡啶-2-磺酸（或羧酸）修饰的玻碳电极

制备了单层级吡啶-2-磺酸 (PySA) 或吡啶-2-羧酸 (PyCA) 修饰的玻碳电极 (GCE)，用于 Cd2+ 和 Pb2+ 的阳极溶出伏安法 (ASV) 分析。PySA 或 PyCA 在 GCE 上通过 PySA 或 PyCA 在 0.5 M H2SO4 水溶液中的电还原共价修饰，产生 PySA/GCE 或 PyCA/GCE。通过X射线光电子能谱和电化学技术表征电极。结合原位铋膜法，PySA/GCE 和 PyCA/GCE 为 Cd2+ 和 Pb2+ 的 ASV 分析提供了非常高的分析性能，包括非常低的检测限值 (LOD，S/N = 3)和高稳定性。PySA/GCE 给出的 Cd2+ 的 LOD 为 4 ppt，Pb2+ 的 LOD 为 7 ppt。PyCA/GCE 给出的 Cd2+ 的 LOD 为 7 ppt，Pb2+ 的 LOD 为 11 ppt。Cu2+ 和 Ni2+ 干扰，这仍然是 Cd2+ 和 Pb2+ 的 ASV 分析的一个挑战，被发现通过在检测溶液中添加 K4Fe(CN)6 和 Ga(III) 可以很好地抑制。修饰电极用于实际水样中Cd2+和Pb2+的分析，结果令人满意。