LAUSR

Abstract Up to now, most electromembrane extraction methods describe the use of pure organic solvents or mixtures as supported liquid membrane. However, the need to incorporate carriers in the supported liquid membrane to achieve the extraction of high polar compounds, seems to indicate that the presence of certain additives in the organic solvent may improve the extraction yield. For this reason, some studies have tried to enhance electrokinetic migration in different ways, modifying either the supported liquid membrane or even the donor solution. In this work, it has been studied and optimized an electromembrane extraction of five widely used non-steroidal anti-inflammatory drugs: salicylic acid, ketoprofen, naproxen, diclofenac and ibuprofen. The thickness and porosity of the support, the supported liquid membrane composition, the donor and acceptor phase pH, the voltage, the extraction time and the electrode configuration were optimized. supported liquid membrane was modified by adding different amounts of Aliquat®336, a cationic carrier commonly used in electromembrane extraction procedure for anionic compounds. The results compared with those obtained in the same extraction conditions using the pure organic solvent as supported liquid membrane, showed better extraction recoveries. The highest recoveries were achieved using a pH 5 donor phase and an acceptor phase at pH 12. The recoveries were within the range of 39 and 53% after 12 minutes extraction, using a voltage of 80V, a stirring speed of 400 rpm and 1-nonanol modified with Aliquat®336 2.5% (w/v) as support liquid membrane. Detection and quantitation limits were within 0.02-1.0 ng mL-1 and 0.05-3.0 ng mL-1, respectively. The selected analytes were extracted by electromembrane extraction using a home-made device designed with a flat configuration. The analyses were carried out by high performance liquid chromatography with diode array and fluorescence detection and finally, applied to the analysis of human urine samples.