Development of a screen-printed gold electrode-based electrochemical sensor for the detection of ephedrine in legal and illicit preparations†

Abstract

In this study, the development of a voltammetric method for the sensitive and selective determination of ephedrine (EPD⁺) using a commercially available screen-printed gold electrode (SPE/Au) was presented. Ephedrine, as a stimulant and performance-enhancing drug, is commonly found in pharmaceutical formulations and is also a target analyte in illicit drug monitoring. Optimizing the electrochemical response, assessing key analytical parameters such as pH, accumulation time, and scan rate to maximize sensitivity and reproducibility, was studied by employing differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The developed method exhibited excellent linearity over a broad concentration range, with a limit of detection (LOD) as low as 0.06 μM and a relative standard deviation (RSD) below 4.3%, confirming its reliability. This electroanalytical approach was successfully validated by quantifying EPD⁺ in pharmaceutical formulations, achieving high recovery rates (98.47–101.27%), demonstrating its applicability for routine quality control. This method offers a rapid, cost-effective, and environmentally friendly alternative to conventional chromatographic techniques, making it a promising tool for pharmaceutical analysis and forensic applications.