Desenvolvimento de um método simples, portátil e de baixo custo para a detecção eletroquímica de efedrina em suplementos alimentares

Abstract

Problems related to the tampering of natural medicines to increase their effectiveness are quite common nowadays. Ephedrine is among the substances often added in dietary supplements to improve or potentiate pharmacological effects related to weight loss. However, several studies have shown various side effects after the consumption of the substance. In 2004, in the United States, the sale of supplements containing ephedrine was banned and considered as adulterated any supplement in which it was found. This work investigated the potential of the Batch Injection Analysis (BIA) coupled to square wave voltammetry (SWV) using boron-doped diamond (BDD) as the working electrode for the analysis of adulterations. The method was used for the development of a simple, low cost and portable analysis procedure for rapid screening of ephedrine in samples of food supplements and herbal supplements (green tea, garcinia, compound garcinia, Lipo Diet Emagry®, spirulina, Thermodrol®). For this purpose, the samples require only one preparation step, consisting of dissolution in the electrolyte support before the analysis. Using optimized experimental conditions, a linear range of 5.0 to 40.0 mg L-1 for ephedrine with a detection limit of 0.13 mg L-1 was obtained in acetic acid/acetate buffer 0.1 mol L- 1, pH = 4.75. The method proposed in this work was shown to be a promising tool for the application in adulteration analyzes in real samples.