Pyridine-2-sulfonic (or carboxylic) acid modified glassy carbon electrode for anodic stripping voltammetry analysis of Cd2+ and Pb2.

Pyridine-2-sulfonic (or carboxylic) acid modified glassy carbon electrode for anodic stripping voltammetry analysis of Cd2+ and Pb2.
Anal Chim Acta. 2020 Oct 23;1135:20-28
Authors: Xiao H, Wang W, Pi S, Cheng Y, Xie Q
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 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.
PMID: 33070855 [PubMed]

Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Xiao H, Wang W, Pi S, Cheng Y, Xie Q Tags: Anal Chim Acta Source Type: research