title: Electromembrane extraction combined with cyclodextrin-modified capillary electrophoresis for the quantification of trimipramine enantiomers.
abstract: A sensitive, simple and reproducible method was developed for preconcentration and determination of trimipramine (TPM) enantiomers in biological samples using electromembrane extraction combined with cyclodextrin-modified capillary electrophoresis (CE). During the extraction, TPM enantiomers migrated from a 5 mL sample solution through a thin layer of 2-nitrophenyl octyl ether NPOE immobilized in the pores of a hollow fiber, and into a 20 μL acidic aqueous acceptor phase presented inside the lumen of the fiber. A Box-Behnken design and the response surface methodology (RSM) were used for the optimization of different variables on extraction efficiency. Optimized extraction conditions were: NPOE as supported liquid membrane, inter-electrode distance of 5 mm, stirring rate of 1000 rpm, 51 V potential difference, 34 min as the extraction time, acceptor phase pH 1.0 and donor phase pH 4.5. Then, the extract was analyzed using optimized cyclodextrin (CD)-modified CE method for the separation of TPM enantiomers. Best results were achieved using 100 mM phosphate running buffer (pH 2.0) containing 10 mM α-CD as the chiral selector, applied voltage of 18 kV and 20°C. The range of quantitation for both enantiomers was 20-500 ng/mL. The method was very reproducible so that intra- and interday RSDs (n=6) were <6%. The limits of quantitation and detection for both enantiomers were 20 and 7 ng/mL, respectively. Finally, this method was successfully applied to determine the concentration of TPM enantiomers in plasma and urine samples without any pre-treatment.
authors.affiliation: Department of Chemistry, Faculty of Sciences, Shahid Beheshti University, Evin, Tehran, Iran. a-zavareh@sbu.ac.ir
authors.forename: Ali R
authors.initials: AR
authors.lastname: Fakhari
authors.forename: Hadi
authors.initials: H
authors.lastname: Tabani
authors.forename: Saeed
authors.initials: S
authors.lastname: Nojavan
authors.forename: Hamid
authors.initials: H
authors.lastname: Abedi
mesh_terms: D000704:Analysis of Variance; D003505:Cyclodextrins / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction / Q000379:methods*; D008567:Membranes, Artificial; D015203:Reproducibility of Results; D012965:Sodium Chloride; D013237:Stereoisomerism; D014299:Trimipramine / Q000032:analysis* / Q000097:blood / Q000737:chemistry* / Q000652:urine
chemical_list: D003505:Cyclodextrins; D008567:Membranes, Artificial; D012965:Sodium Chloride; D014299:Trimipramine