Speciation of Arsenic by Potentiometric Stripping Analysis Using Gold(III) Solution as Chemical Reoxidant and a Wall‐Jet Flow Cell

Abstract

A simple procedure is described for the potentiometric stripping of arsenic with a wall-jet cell by means of potentiostatic co-deposition of gold and arsenic at a glassy-carbon electrode and subsequent chemical stripping with Au(III). Optimum medium containing 160 mg L À1 of Au(III) in HCl 0.1 M, where it is possible to speciate As(III) and As(V). As(V) was electrodeposited directly without prior chemical reduction at working electrode. As(III) was first determined at an electrodeposition potential of À 0.1 V. Afterwards, total arsenic was determined by an electrodeposition potential of À 0.7 V, from the area of peak obtained of the differential stripping potentiogram by using the standard addition method. The original As(V) concentration in the sample was calculated by difference. The possibilities of the optimized method were demonstrated by determinations of As(III), As(V) and total arsenic in samples of polluted water.

Flagellin-based electrochemical sensing layer for arsenic detection in water

“…Although arsenic is predominantly present in nature in the form of As(V), its direct electrochemical detection at neutral pH is considered to be almost impossible, due to the extreme stability and thus electrochemical inactivity of this oxidation state 34 , 35 . In contrast, electrochemical detection of As(III) is relatively simple at the same pH range.…”

Potentiometric Stripping Analysis of Cadmium and Lead with Constant Inverse Current in the Analytical Step Using an Open Tubular Mercury-Coated Glassy Carbon Electrode

“…Depending on the type of the sample, the required capacity and speed (frequency) of the measurement, numerous flow electrochemical cells have been applied. The most commonly used cell constructions are “flow through” [10, 12, 13, 21, 22, 24–28], “thin layer (channel),” [12, 15–20] and “wall-jet” [1, 29–31]. In recent times, graphite-felt electrode [32], carbon fibre-loaded electrode [5], microflow cell [33], microflow cell with screen-printed electrode [34, and screen-printed carbon nanotube electrode [6] have also been applied.…”

“…The flow-stripping measurements are more often applied within the environmental surveillance, then within a food and beverages control, and in the clinical investigations, that is, the analysis of biological material. Numerous works deal with determining the trace metals (Zn, Cd, Pb, Cu, Hg, Ni, and Co) in various water samples, including wastewater [3, 10, 13, 21, 22, 27, 29], in food (heavy metals, As, and Se) [6, 12, 16, 18, 25, 26, 28], and in biological materials (Se) [20].…”