Highly sensitive determination of vanadium (V) by catalytic adsorptive stripping voltammetry. Substituent effect on sensitivity III

CATEGORY: VANADIUM
Highly sensitive determination of vanadium (V) by catalytic adsorptive stripping voltammetry. Substituent effect on sensitivity III

Type	Journal Article
Author	Carlos Rojas-Romo
Author	Verónica Arancibia
URL	http://www.sciencedirect.com/science/article/pii/S0925400515305608
Volume	224
Pages	772-779
Publication	Sensors and Actuators B: Chemical
Date	March 1, 2016
Abstract	Catalytic adsorptive stripping voltammetry is a powerful technique for trace metal determination. Authors report one of the most sensitive voltammetric methods developed for vanadium. The determination is based on the complexation of vanadium with quercetin-5-sulfonic acid (QSA), adsorption of V(V)-QSA and reduction to V(III)-QSA onto HMDE; and finally in the scan step electrochemical reduction of V(III)-QSA to V(II) at about −0.78 V applying differential pulse catalytic adsorptive stripping voltammetry. In order to compare the effect of the sulfonic group on the sensitivity of the determination, researchers developed two methods using quercetin (Q) and Quercetin-5-sulfonic acid (QSA) as complexing and adsorbing ligands. The effects of various operational parameters such as pH, ligand, and potassium bromate concentration (CQ, CQSA, CKBrO3), potential, and adsorption time (Eads, tads) were optimized. The best results were obtained with QSA, and the optimal experimental parameters were pH: 7.0; CQSA: 0.6 × 10−6 mol L−1, CKBrO3: 3.5 × 10−2 mol L−1, Eads: 0.0 V, and tads: 30 s. The method was applied to the determination of vanadium in tap water, purified drinking water, river water, and commercial water for chromatography.