This paper presents for the first time the use of an environmentally friendly solid bismuth microelectrode for the voltammetric quantification of V(V) in natural water samples. These studies were designed to replace the film bismuth electrode that had been introduced to eliminate the conventional sensors based on highly toxic mercury. In the proposed procedure, V(V) is preconcentrated at the solid bismuth microelectrode surface via the formation of electroactive complexes with cupferron from a solution of 0.1-mol L−1 acetate buffer, pH = 4.6 at a potential of −0.4 V. The linearity of the calibration graph is in the V(V) concentration range from 8 × 10−10 to 1 × 10−7 mol L−1 with a preconcentration time of 1 min. The limit of detection (calculated as 3 σ) is 2.5 × 10−10 mol L−1 for a preconcentration time of 1 min. It was also demonstrated that significant improvement in analytical parameters was achieved as a result of the activation of the solid electrode surface at a potential of −2.5 V for 2 s. The developed procedure is highly selective for the presence of foreign ions and organic compounds in tested samples. The accuracy of the recommended procedure was checked using SPS-WW1 waste water-certified reference materials of a complex composition, in which the concentration of V(V) determined by the proposed method was 95.1 ± 1.6 ng mL−1. Moreover, in keeping with the outlined procedure, river, tap and rain water samples were analyzed without any pretreatment, and recovery values from 96% to 106% were obtained.
We report the use of carbon nanotubes as a material for the preparation of an electrochemical sensor that acts as a substrate for film metal electrodes used in stripping voltammetry. The sensor is based on a mixture of multiwall carbon nanotubes, glassy carbon spherical powder, and epoxy resin. The properly selected composition of the sensor made it possible to obtain a new substrate, competitive in relation to glassy carbon, for creating film metal electrodes. In this work, the proposed new sensor was used to determine the trace amounts of Ti(IV) on the lead film electrode. Measurements were carried out with in situ mode in an acetate buffer by adsorption stripping voltammetry with the use of cupferron as a complexing agent. Linear response to Ti(IV) ions in the concentration range of 7 × 10–10–7 × 10–8 mol L−1 and the limit of detection (LODs) 2.4 × 10–10 were obtained, respectively. These promising results revealed that a mixture of carbon nanotubes, epoxy resin, and spherical glassy carbon powder used for the determination of titanium ions on PbFE might represent an important addition to existing electrochemical sensor technologies. The proposed procedure was successfully used as a new and powerful analytical tool for determination of Ti(IV) in horsetail extracts.
In this paper, an activated bismuth layer formed in situ on a solid bismuth microelectrode, used as a working electrode for the electrochemical sensitive determination of Ga(III), based on anodic stripping voltammetry (ASV) is discussed. The new electrode significantly enhances the sensitivity in the ASV determination of Ga(III) and exhibits superior performance in comparison to a bismuth film electrode prepared on a glassy carbon disc. The experimental variables, such as the potential and time of solid-bismuth-microelectrode activation, the composition of the supporting electrolyte, and the influence of possible interferences on the Ga(III) signal response, were tested. The most favorable values were selected (pH = 4.6; acetate buffer; activation potential/time: −1.8 V/6 s and −1.4 V/60 s). In the optimized conditions, the peak current was found to be proportional to the concentration of Ga(III) over the range from 2 × 10−8 to 2 × 10−6 mol L−1 with R = 0.993. The limit of detection (LOD) was 7 × 10−9 mol L−1. Finally, the proposed method was successfully applied for gallium determination in certified reference waters, such as surface water and waste water, as well as tap and river water samples. The water samples were analyzed without any pretreatment and recovery values from 92.4 to 105.5% were obtained.
The main purpose of this review is to present methods of adsorptive stripping voltammetry that can be used to determine trace amounts of VO2(+) in various types of samples. The detection limits achieved using different working electrodes are presented. The factors influencing the obtained signal, including the selection of the complexing agent and the selection of the working electrode, are shown. For some methods, in order to increase the range of applied concentrations in which vanadium can be detected, a catalytic effect is introduced to adsorptive stripping voltammetry. The influence of the foreign ions and organic matter contained in natural samples on the vanadium signal is analyzed. This paper presents methods of elimination associated with the presence of surfactants in the samples. The methods of adsorptive stripping voltammetry for the simultaneous determination of vanadium with other metal ions are also characterized below. Finally, the practical use of the developed procedures, mainly for the analysis of food and environmental samples, is summarized in a tabular version.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.