title: Determination of dihydroetorphine in biological fluids by gas chromatography-mass spectrometry using selected-ion monitoring.
abstract: A method for the determination of dihydroetorphine hydrochloride, a powerful anaesthetic and analgesic drug, in biological fluids by GC-MS with selected-ion monitoring using etorphine as internal standard was established. Dihydroetorphine was extracted from human blood and urine with dichloromethane and then derivatized with N-heptafluorobutyrylimidazole after concentration to dryness. A dihydroetorphine monoheptafluorobutyl derivative was formed which showed good behavior on GC-MS with electronic-impact ionization. The main fragment, m/z 522, which is the base peak, was selected as the ion for quantitation and the corresponding ion, m/z 520, was selected for monitoring the internal standard, etorphine. The recoveries and coefficients of variation of the whole procedure were determined with five controlled dihydroetorphine-free urine and plasma samples spiked with different concentrations of dihydroetorphine. The concentration of dihydroetorphine for quantitation was in the range 1-20 ng/ml for urine and 2.5-250 ng/ml for plasma. The correlation coefficients of the standard curves are sufficient to determine the dihydroetorphine. The accuracy for quantitation of dihydroetorphine in urine and plasma is less than 10.6%.
authors.affiliation: Institute of Pharmacology and Toxicology, Beijing, China.
authors.forename: F
authors.initials: F
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Luo
authors.forename: J
authors.initials: J
authors.lastname: Feng
authors.forename: X
authors.initials: X
authors.lastname: Hu
mesh_terms: D000701:Analgesics, Opioid / Q000032:analysis* / Q000097:blood / Q000652:urine; D002138:Calibration; D005048:Etorphine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009293:Opioid-Related Disorders / Q000517:prevention & control; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry
chemical_list: D000701:Analgesics, Opioid; D012997:Solvents; D005048:Etorphine; C034765:18,19-dihydroetorphine