title: Simultaneous determination of tramadol, O-desmethyltramadol and N-desmethyltramadol in human urine by gas chromatography-mass spectrometry.
abstract: Analytical procedures for the determination of tramadol (T), O-desmethyltramadol (ODT), and N-desmethyltramadol (NDT) in human urine have been developed and validated using gas chromatography-mass spectrometry (GC/MS). Sample preparation involved liquid-liquid extraction with methyl-tert-butyl ether (MTBE) and followed by back extraction with 0.1 M hydrochloric acid. Proadifen (SKF525A) was selected as internal standard (IS). Extraction efficiencies of T, ODT and NDT were 102.12, 101.30, and 98.21%, respectively. The calibration curves were linear (r(2)>0.99) in the concentration range 10-1000 ng/mL for all compounds. Limits of quantification (LOQ) were 10, 10 and 20 ng/mL for T, ODT and NDT, respectively. Intra-assay precision was within 1.29-6.48% and inter-assay precision was within 1.28-6.84% for T, ODT and NDT. Intra-assay accuracy was within 91.79-106.89% for all analytes. This method detected urine concentrations of T, ODT and NDT in six healthy volunteers for 7 days after administration of 50 mg oral doses of tramadol.
authors.affiliation: Chemistry Department, Faculty of Science, Al-Azhar University, Egypt. ayossefelsayed@yahoo.com
authors.forename: Abdel-Aziz Y
authors.initials: AA
authors.lastname: El-Sayed
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Mohamed
authors.forename: Ahmed Y
authors.initials: AY
authors.lastname: Nasser
authors.forename: Jennifer
authors.initials: J
authors.lastname: Button
authors.forename: David W
authors.initials: DW
authors.lastname: Holt
mesh_terms: D000701:Analgesics, Opioid / Q000737:chemistry / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D012015:Reference Standards; D015203:Reproducibility of Results; D014147:Tramadol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000652:urine*
chemical_list: D000701:Analgesics, Opioid; C080580:O-demethyltramadol; D014147:Tramadol; C080579:N-demethyltramadol