Carrier assisted electromembrane extraction based on nonionic lipophilic surfactants for the determination of basic drugs in urine samples

Abstract

Herein, an efficient carrier assisted electromembrane extraction coupled with capillary electrophoresis has been proposed for the quantitation of basic drugs (pseudoephedrine and tramadol) in urine samples. Nonionic lipophilic surfactants in the supported liquid membrane act as carriers and promote the migration of ionic analytes toward the acceptor phase. The volumes of the sample and acceptor solutions were 4000 and 20 μL, respectively. All variables affecting the extraction efficiency were investigated for the proposed method. Optimal extractions were accomplished with 2-nitrophenyl octyl ether, containing 0.25 mM Span 80 as the supported liquid membrane, with 200 V as the driving force and with pH 5.0 in donor and pH 1 in acceptor solutions. Extractions were obtained after 30 min of operation with the whole assembly agitated at 1000 rpm. Under the optimum experimental conditions, the linear range was 10–2000 and 5–2000 ng mL⁻¹ for pseudoephedrine and tramadol, respectively (R² ≥ 0.99). The limits of detection were calculated to be 3.03 and 1.51 ng mL⁻¹ for pseudoephedrine and tramadol, respectively. The relative standard deviation was lower than 4.1%. The enrichment factors were in the range of 178 to 188. The method was successfully applied for the analysis of these drugs in urine samples.