吡啶-2-磺酸（或羧酸）修饰玻碳电极用于 Cd 和 Pb 的溶出伏安分析。

Pyridine-2-sulfonic (or carboxylic) acid modified glassy carbon electrode for anodic stripping voltammetry analysis of Cd and Pb.

机构信息

Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, PR China; College of Science, Central South University of Forestry and Technology, Changsha, 410004, PR China.

College of Science, Central South University of Forestry and Technology, Changsha, 410004, PR China.

出版信息

Anal Chim Acta. 2020 Oct 23;1135:20-28. doi: 10.1016/j.aca.2020.08.024. Epub 2020 Aug 21.

DOI:10.1016/j.aca.2020.08.024

PMID:33070855

Abstract

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 Cd and Pb. PySA or PyCA was covalently modified on GCE by electroreduction of PySA or PyCA in 0.5 M aqueous HSO, 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 Cd and Pb, 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 Cd or of 7 ppt for Pb. The PyCA/GCE gave a LOD of 7 ppt for Cd or of 11 ppt for Pb. The Cu and Ni interferences, which still appear as a challenge for ASV analysis of Cd and Pb, were found to be well inhibited by the additions of KFe(CN) and Ga(III) into the detection solution. The modified electrode was used for Cd and Pb analysis in real water samples with satisfactory results.

摘要

单层吡啶-2-磺酸 (PySA) 或吡啶-2-羧酸 (PyCA) 修饰玻碳电极 (GCE) 用于 Cd 和 Pb 的阳极溶出伏安法 (ASV) 分析。通过在 0.5 M 水溶液 HSO 中电还原 PySA 或 PyCA，将 PySA 或 PyCA 共价修饰到 GCE 上，得到 PySA/GCE 或 PyCA/GCE。通过 X 射线光电子能谱和电化学技术对电极进行了表征。结合原位铋膜法，PySA/GCE 和 PyCA/GCE 均为 Cd 和 Pb 的 ASV 分析提供了非常高的分析性能，包括非常低的检测限 (LOD，S/N = 3) 和高稳定性。PySA/GCE 对 Cd 的 LOD 为 4 ppt，对 Pb 的 LOD 为 7 ppt。PyCA/GCE 对 Cd 的 LOD 为 7 ppt，对 Pb 的 LOD 为 11 ppt。在检测溶液中加入 KFe(CN) 和 Ga(III) 可有效抑制 Cu 和 Ni 的干扰，这仍然是 Cd 和 Pb 的 ASV 分析面临的挑战。修饰电极用于实际水样中 Cd 和 Pb 的分析，结果令人满意。