Influence of Electrode Polishing Protocols, Potentiostat Models, and LOD Calculation Methods on the Electroanalytical Performance of SWV Measurements at Glassy Carbon Electrodes

Abstract

The aim of this study was to evaluate how fundamental elements of electrochemical measurements influence the results of electroanalytical procedures. Measurements were performed using square wave voltammetry at a glassy carbon electrode, and the analytical signal corresponded to a model redox system.

One objective of the study was to examine the impact of potentiostats from different manufacturers, as well as differences between models within the same brand, which varied considerably in cost and measurement capabilities.

The influence of the mechanical cleaning procedure for the solid disc electrode surface was also investigated. Three types of polishing motion and different numbers of repetitions were tested. The results showed that polishing motion significantly affects the electroactive surface area of the working electrode and the repeatability of measurements. The largest electroactive surface area and the best repeatability were obtained when polishing was performed using an “8-shaped” motion on the polishing pad.

The results confirmed that both instrumentation and electrode polishing procedures can substantially influence statistical parameters describing analytical methods, such as the limit of detection (LOD) and the dynamic range of the calibration curve. Furthermore, applying different approaches for LOD estimation to the same dataset may lead to discrepancies reaching up to two orders of magnitude.