Anodic stripping voltammetry with graphite felt electrodes for the trace analysis of silver

Abstract

Graphite felt (GF) is a mass produced porous carbon electrode material commonly used in redox flow batteries. Previous studies have suggested GF may have valuable applications in electroanalysis as a low cost disposable carbon electrode material, although most GF sensors have used flow cell arrangements. In this work, an elegant wetting technique is employed that allows GF electrodes to be used in quiescent solution to detect trace levels of silver in water via anodic stripping voltammetry. GF electrodes display good repeatability and a limit of detection of 25 nM of Ag(+) in 0.1 M HNO3, with a linear range spanning two orders of magnitude. This compares to a value of around 140 nM when using conventional carbon electrodes. Combined with their low cost and disposable nature, the results suggest GF electrodes can make a valuable contribution to electroanalysis.

Detection and Determination of Released Ions in the Presence of Nanoparticles: Selectivity or Strategy?

“…The repeatability was 13.6 % for HC and 8.5 % for LC, which are in accordance with values adopted in the validation guides of bioanalytical methods, which allows a variation of up to 25 % in the lower control and up to 15 % in the upper control . Values obtained were also in agreement with other electroanalytical methods which present about 10 % variability .…”

“…The linearity of methods for Ag + detection have been reported within working ranges similar to ours .…”

“…Using the instrumental parameters listed in 2.3 it was possible to obtain a single peak at 0.240±0.008 V. The differences between the baseline of each measurement is due to the differences between the compositions of both samples. Other articles showed differences in baseline levels in the blank and standard . Conditions in which two signals were obtained were discarded.…”

“…This step is essential in the silver determination because silver deposits are highly stables and in many cases two electrochemical signals are obtained, this fact hinders the exact quantification of the silver ions. Several methods have been described in which acid solutions of different electrolytes are used to improve the electro‐dissolution .…”

Steady‐State Measurements of Vanadium Redox‐Flow Batteries to Study Particular Influences of Carbon Felt Properties

“…Carbon felts are well‐established materials in thermal insulation applications, and their industrial introduction dates back to the late 1960s . Due to their high electronic conductivity and large surface area, they were used soon afterwards in electrochemical synthesis, water purification, electrochemical analysis or batteries . With the resurfacing interest in redox flow batteries during the last few years, activities aiming at a deeper understanding and further improvement of these porous carbon materials have been intensified .…”