Highly sensitive determination of vanadium (V) by catalytic adsorptive stripping voltammetry. Substituent effect on sensitivity III
| Autor: | Carlos Rojas-Romo, David Moreno da Costa, Ricardo A. Tapia, Verónica Arancibia |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Detection limit
010401 analytical chemistry Inorganic chemistry Metals and Alloys Vanadium chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Electrochemistry 01 natural sciences Purified water 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Adsorption chemistry Tap water Adsorptive stripping voltammetry Materials Chemistry Electrical and Electronic Engineering 0210 nano-technology Potassium bromate Instrumentation |
| Zdroj: | Sensors and Actuators B: Chemical. 224:772-779 |
| ISSN: | 0925-4005 |
| DOI: | 10.1016/j.snb.2015.10.094 |
| Popis: | Catalytic adsorptive stripping voltammetry has been a powerful technique for trace metal determination. We now 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. With the aim of comparing the effect of the sulfonic group on the sensitivity of the determination, two methods were developed 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 (C Q , C QSA , C KBrO3 ), potential, and adsorption time ( E ads , t ads ) were optimized. The best results were obtained with QSA, and the optimal experimental parameters were pH: 7.0; C QSA : 0.6 × 10 −6 mol L −1 , C KBrO3 : 3.5 × 10 −2 mol L −1 , E ads : 0.0 V, and t ads : 30 s. Under the best experimental conditions the RSD for a V(V) solution (0.1 μg L −1 ) was 3.4% for ten successive assays. Linearity was maintained up to 0.35 μg L −1 and the detection limit was 0.23 ng L −1 ( t ads : 30 s; C QSA : 0.6 × 10 −6 mol L −1 ). The method was validated using certified reference water (TMDA – 61.2) and finally, the method was applied to the determination of vanadium in tap water, purified drinking water, river water, and commercial water for chromatography. |
| Databáze: | OpenAIRE |
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