tExtraction of polar endogenous compounds remains an important issue in bioanalysis although differenttechniques have been evaluated. Among them, electromembrane extraction (EME) is a relevant approachbut supported liquid membranes (SLMs) dedicated to polar molecules are still lacking. In this study 22organic solvents were evaluated as SLMs on a set of 45 polar basic metabolites (log P from −5.7 to1.5) from various biochemical families. To investigate a large variety of organic solvents, a parallel elec-tromembrane extraction device was used and a constant current approach was applied to circumventthe heterogeneous conductivities of the different SLMs. Among the tested organic solvents, 2-nitrophenylpentyl ether (NPPE) appeared the most efficient SLM with the extraction of a large variety of polar cationicmetabolites, high extraction yields, and low extraction variabilities. The applied current and the compo-sition of the acceptor and donor solutions were also evaluated and 300 A per well and acetic acid 1%(v/v), both as acceptor and donor compartments, were the most efficient conditions. The new SLM and theoptimized experimental parameters were successfully applied to the extraction of precipitated plasmasamples. Although the extraction recovery decreased for most compounds in the biological matrix, pro-cess efficiency (PE) up to 90% and low extraction variability (RSD between 2 and 18%) were obtainedfor several very polar compounds such as choline or acetylcholine, emphasizing the potential of EME forpolar compounds.