Review—Voltammetric Determination of Heavy Metals with Carbon-Based Electrodes

Abstract

Determination of heavy metals is still a relevant pursuit due to the ongoing incidents of contamination and continuous anthropogenic and industrial activities. Spectrometric methods such as atomic absorption are the most common approaches to this task because of the high accuracy and sensitivity they provide. Nevertheless, these methods are costly, time-consuming, and do not allow for on-site measurements. Considering recent developments in electrochemistry, especially voltammetric methods, conducting trace-level heavy metal analysis has become easier, faster, and cheaper. Utilizing a carbon-based electrode (CBE) for this purpose seems to further improve the performance of the above-mentioned methods. CBEs are versatile, offer a wide potential window, and possess desirable conductive and surface properties that allow sensitive determination of analytes. This review aims to examine the recent studies published between 2015 and 2020 which investigated the performance of carbon-based electrodes in heavy metal determination, by placing the four most common carbon electrodes to the center: glassy carbon electrode, graphite electrode, carbon paste electrode, and screen-printed carbon electrode.

Practical Strategy for Arsenic(III) Electroanalysis without Modifier in Natural Water: Triggered by Iron Group Ions in Solution

“…It is worth noting that As­(III) reduction usually requires the adsorption of As­(III) at the electrode surface. However, As­(III) cannot be adsorbed at the GCE without the assistance of other analytes or electrode modifiers . Furthermore, Fe 0 may work as an absorbent in the first stage of As­(III) reduction, considering that Fe 2+ can be reduced to Fe 0 and the nanosized Fe 0 particles are favorable for adsorbing heavy metals .…”

“…However, As(III) cannot be adsorbed at the GCE without the assistance of other analytes or electrode modifiers. 39 Furthermore, Fe 0 may work as an absorbent in the first stage of As(III) reduction, considering that Fe 2+ can be reduced to Fe 0 and the nanosized Fe 0 particles are favorable for adsorbing heavy metals. 40 To examine this assumption, the deposits obtained from As(III) solution, Fe 2+ solution, the mixture solution of Fe 2+ and As(III), and the mixture solution of Fe 3+ and As(III) are analyzed via SEM and EDS, which are aimed to confirm whether the composition of deposits was single or multiple components, as shown in Figures 5 and S8.…”

Electrochemical detection of Pb(ii) and Cd(ii) using bismuth ferrite nanoparticle modified carbon paste electrodes

“…1,2 Heavy metals such as lead, cadmium, chromium, zinc and mercury, which are non-degradable and the most persistent pollutants in the environment, are the most critical since they seriously affect human health. [3][4][5] Heavy metals can accumulate not only in the soil environment but also in plants and groundwater, which may cause adverse effects to the ecosystem safety and pose a threat to animals, plants, and humans. 4,5 Heavy metals can enter living organisms and the human body via the food chain leading to the slowing of the progression of physical, muscular, and neurological, degenerative processes and incremental of chronic diseases such as cancer.…”

“…1,2 Heavy metals such as lead, cadmium, chromium, zinc and mercury, which are non-degradable and the most persistent pollutants in the environment, are the most critical since they seriously affect human health. 3–5 Heavy metals can accumulate not only in the soil environment but also in plants and groundwater, which may cause adverse effects to the ecosystem safety and pose a threat to animals, plants, and humans. 4,5…”

Selective detection of Cu2+ ions using a mercaptobenzothiazole disulphide modified carbon paste electrode and bismuth as adjuvant: a theoretical and electrochemical study

“…These types of electrodes have been widely used in the quantitative and qualitative determination of heavy metals. 4 This is because the surface of these electrodes can be modified by adding organic and/or inorganic compounds that give them greater sensitivity and selectivity for a particular analyte. 5 Also, these electrodes have advantages such as, low cost, simple design, low background current, easy removal of electrode surface layer (renewal), low ohmic resistance, mechanical stability, and a wide potential range.…”