Method for determining amphetamine in the presence of caffeine and paracetamol

Abstract

The subject of the application is a method for the rapid, simple, quantitative, and qualitative determination of amphetamine. The method is characterized in that two pairs of electrodes are introduced into a suitably constructed electrochemical vessel (1), consisting of two parts filled with an organic phase (a base electrolyte solution) and an aqueous phase containing a base electrolyte solution (a salt that dissociates into ions with a low partition coefficient). One pair of reference electrodes (1, 4) is an Ag / AgCl-coated wire, and one pair of auxiliary electrodes (2, 5) is made of platinum. All electrodes are then connected to a potentiostat, which enables potentiostatic polarization of the liquid-liquid phase boundary (3).The amphetamine sample being tested is dissolved in an aqueous phase containing a stock electrolyte solution with a pH lower than the amphetamine pKa, and undergoes a controlled interfacial transition across the liquid-liquid phase boundary (3). The transition of the amphetamine molecule is recorded using electroanalytical methods, such as voltammetric analysis. The potential applied from an external polarization source provides qualitative information, while the recorded Faradaic currents provide quantitative information. Determination of the amphetamine concentration is based on standard calibration methods.