title: Modified solvent microextraction with back extraction combined with liquid chromatography-fluorescence detection for the determination of citalopram in human plasma.
abstract: A modified solvent microextraction with back extraction method (SME/BE) combined with high performance liquid chromatography and fluorescence detection (HPLC-FD) was developed for the determination of citalopram in human plasma. Extraction process was performed in a home-made total glass vial without using a teflon ring, usually employed in SME/BE. Citalopram was first extracted from 0.5 mL of plasma, modified with sodium hydroxide, into hexane. Back extraction step was then performed into 5.2 microL of 45 mM ammonium formate solution (pH 4) using a GC microsyringe. The extract was subsequently transferred into a liner-like vial and then injected into the HPLC system. An enrichment factor of 150 along with a good sample clean-up was obtained. The calibration curve showed linearity in the range of 1.0-130.0 ng mL(-1) with regression coefficient corresponding to 0.992. This range covers therapeutic window and even lower amounts which is important in pharmacokinetic studies. Limits of detection and quantification, based on a signal to noise ratio (S/N) of 3 and 10, were 0.3 and 0.8 ng mL(-1), respectively. The method was also applied for the determination of citalopram in plasma samples after oral administration of 40 mg single dose of citalopram.
authors.affiliation: Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran. bagheri@sharif.edu
authors.forename: Habib
authors.initials: H
authors.lastname: Bagheri
authors.forename: Faezeh
authors.initials: F
authors.lastname: Khalilian
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Babanezhad
authors.forename: Ali
authors.initials: A
authors.lastname: Es-haghi
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Rouini
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015283:Citalopram / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood*; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D015283:Citalopram; D017367:Selective Serotonin Reuptake Inhibitors; D012997:Solvents