title: Low-voltage electromembrane extraction of basic drugs from biological samples.
abstract: The present work has for the first time demonstrated electromembrane extraction (EME) at voltages obtainable by common batteries. Five basic drugs were extracted from acidified aqueous sample solutions, across a supported liquid membrane (SLM) consisting of 1-isopropyl-4-nitrobenzene impregnated in the walls of a hollow fiber, and into an acidified aqueous acceptor solution present inside the lumen of the hollow fiber with potential differences of 1-10 V applied over the SLM. Extractions from 1 ml standard solutions prepared in 10mM HCl for 5 min and with a potential of 10 V demonstrated analyte recoveries of 50-93% in 25 microl of 10mM HCl as acceptor solution. This corresponds to enrichment factors of 20-37. Similar results were obtained with a common 9 V battery as power supply. Recoveries from low-voltage EME on human plasma, urine, and breast milk diluted with acetate buffer (pH 4) demonstrated recoveries in the range of 37-55% after 5 min of extraction. Excellent selectivity was demonstrated as no interfering peaks were detected. Standard curves in the range of 0.0625-0.62 5 microg/ml demonstrated correlation coefficients of 0.994-0.999. Extraction recoveries from human plasma, urine or breast milk were not found to be sensitive towards individual variations. The results show that low-voltage EME has a future potential as a simple, selective, and time-efficient sample preparation technique of biological fluids.
authors.affiliation: School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway.
authors.forename: Inger Johanne Østegaard
authors.initials: IJ
authors.lastname: Kjelsen
authors.forename: Astrid
authors.initials: A
authors.lastname: Gjelstad
authors.forename: Knut Einar
authors.initials: KE
authors.lastname: Rasmussen
authors.forename: Stig
authors.initials: S
authors.lastname: Pedersen-Bjergaard
mesh_terms: D001826:Body Fluids / Q000737:chemistry*; D004563:Electrochemistry; D006801:Humans; D008567:Membranes, Artificial; D004364:Pharmaceutical Preparations / Q000097:blood / Q000302:isolation & purification* / Q000652:urine
chemical_list: D008567:Membranes, Artificial; D004364:Pharmaceutical Preparations