Determination of trace Se(IV) by anodic stripping voltammetry following double deposition and stripping steps

Microelectrode Voltammetric Analysis of Low Concentrations of Se(IV) Ions in Environmental Waters

The current research is an attempt to analyze on-site selenium(IV) ions in environmental water samples using an eco-friendly miniaturized sensor developed by deposition of a very thin amount of metallic bismuth in a solid Bi electrode tightly closed in miniaturized housing. Numerous experimental variables are optimized, including the composition of the supporting electrolyte and its pH, as well as activation and accumulation conditions. Under optimized measurement conditions, the method shows high sensitivity, permitting a very low limit of detection equal to 7 × 10-10 mol L-1 to be achieved in a short accumulation time of 50 s. The performance of this microsensor was investigated against numerous interference factors and its good anti-interference capability was demonstrated. A series of voltammetric experiments by differential pulse cathodic stripping voltammetry (DPCSV) were carried out and they proved that the miniaturized sensor is characterized by very good accuracy and precision as well as long-term stability. The solid bismuth microelectrode displays a good voltammetric response in the analysis of diverse samples with a complex matrix and demonstrates a good recovery rate.

Thin Film Electrodes for Anodic Stripping Voltammetry: A Mini-Review

Anodic stripping voltammetry (ASV) is a powerful electrochemical analytical technique that allows for the detection and quantification of a variety of metal ion species at very low concentrations in aqueous media. While early, traditional ASV measurements relied on macroscopic electrodes like Hg drop electrodes to provide surfaces suitable for plating/stripping, more recent work on the technique has replaced these electrodes with thin film metal electrodes generated in situ. Such electrodes are plated alongside the analyte species onto the surface of a primary electrode, producing a composite metal electrode from which the analyte(s) can then be stripped, identified, and quantified. In this minireview, we will explore the development and use of these unique electrodes in a variety of different applications. A number of metals (e.g., Hg, Bi, Sn, etc.) have shown promise as thin film ASV electrodes in both acidic and alkaline media, and frequently multiple metals in addition to the analyte of interest are deposited together to optimize the plating/stripping behavior, improving sensitivity. Due to the relatively simple nature of the measurement and its suitability for a wide range of pH, it has been used broadly: To measure toxic metals in the environment, characterize battery materials, and enable biological assays, among other applications. We will discuss these applications in greater detail, as well as provide perspective on future development and uses of these thin film electrodes in ASV measurements.

New Strategies for the Simple and Sensitive Voltammetric Direct Quantification of Se(IV) in Environmental Waters Employing Bismuth Film Modified Glassy Carbon Electrode and Amberlite Resin

An analytical procedure regarding the determination of selenium(IV) by anodic stripping voltammetry exploiting the in situ plated bismuth film electrode is described. Since organics are commonly present in untreated natural water samples, the use of Amberlite XAD-7 resin turns out to be quite important to avoid problems such as the adsorption of these compounds on the working electrode. The optimum circumstances for the detection of selenium in water using differential pulse voltammetry techniques were found to be as follows: 0.1 mol L-1 acetic acid, 1.9 × 10-5 mol L-1 Bi(III), 0.1 g Amberlite XAD-7 resin, and successive potentials of -1.6 V for 5 s and -0.4 V for 60 s, during which the in situ formation of the bismuth film on glassy carbon and the accumulation of selenium took place. The current of the anodic peak varies linearly with the selenium concentration ranging from 3 × 10-9 mol L-1 to 3 × 10-6 mol L-1 (r = 0.9995), with a detection limit of 8 × 10-10 mol L-1. The proposed procedure was used for Se(IV) determination in certified reference materials and natural water samples, and acceptable results and recoveries were obtained.

Detection of Selenium and Nickel Metal Ion in Water Using Mn3O4-Cn-Modified Electrode

The present study reports the design of the Mn3O4-Cn electrode and its use for simultaneous detection of selenium and nickel in water. The designed electrode can be used as a convenient electrochemical device for on-site testing of Se (IV) and Ni (II) levels in affected regions. The best responses are obtained with 0.1 M phosphate buffer saline (PBS) and 5 mM Fe (CN)6 as supporting electrolyte. The scan rate and the number of cyclic repetitions have a great effect on peak shape and intensity. It is seen from our study that peak intensity is directly proportional to Se (IV) and Ni (II) concentrations in the range of 5 to 250 µg/L (correlation coefficients 0.952 and 0.984) when the optimized parameters are used. The detection limit of 0.533 µg/L Se (IV) and 0.718 µg/L for Ni (VI) with a response time of 18 s for 5–250 µg/L concentration is obtained, respectively. Enhanced analytical results for different water samples establish that the proposed method is appropriate for Se (IV) and Ni (II) detection. FESEM images confirm the Mn3O4-Cn nanocomposite formation on the electrode.

Development and application of a routine robust graphite/poly(lactic acid) composite electrode for the fast simultaneous determination of Pb2+ and Cd2+ in jewelry by square wave anodic stripping voltammetry

A handcrafted, low cost sustainable electrochemical sensor based on graphite/PLA was developed and applied for the simultaneous quantification of Pb²⁺ and Cd²⁺ in jewelry.

Simple multimodal detection of selenium in water and vegetable samples by a catalytic chromogenic method

The determination of selenium (Se) has garnered increasing interest because of its importance to life as a nutrient element as well as its toxicological effects.