Ephedrine Analysis in Real Urine Sample via Solvent Bar Microextraction Technique Coupled with HPLC-UV and Chemometrics

Background: Ephedrine, an alpha/beta-adrenergic agonist, is one of the most common doping agents not only among athletes but also the ordinary people, therefore its detection at low trace levels with a sensitive and cost effective method has become a priority to investigate many analytical methods. Objective: In this work, solvent bar microextraction followed by high-performance liquid chromatography (HPLC-UV) was used for extraction and determination of ephedrine at low trace levels from urine samples at optimum condition. Methods: In this study, a designed experiment was carried out using solvent bar microextraction technique, which has been proved to be a green method. This method requires three phases consisting of a donor phase with an alkaline pH, an acceptor phase with an acidic pH, and organic solvent to impregnate the pores of the hollow fiber. The obtained results were used for estimating the optimum ranges for each parameter, analyzing the effect of different parameters, simultaneously. Results: Under optimized circumstances, the preconcentration factor was 129. The calibration curves represented good linearity for urine sample with coefficient estimations higher than 0.9991. The limit of detection and quantitation for ephedrine were 16.7 μg L-1 and 50 μg L-1, respectively. The relative standard deviations of analysis were 3.5% within a day (n=3) and 4.1% between days (n=9). Conclusion: According to the results and previous studies, it can be concluded that the preconcentration factor for ephedrine was the best result ever reported considering selectivity and cost-effectiveness.