title: Quantitative analysis of RU38486 (mifepristone) by HPLC triple quadrupole mass spectrometry.
abstract: A sensitive liquid chromatography-mass spectrometric method was validated for the quantification of RU38486 (mifepristone) in human and murine plasma. The analyte and internal standard (alfaxolone) were extracted by liquid-liquid extraction with diethyl ether, resolved on a C18 column using gradient elution with methanol and ammonium acetate and detected after positive electrospray ionization (m/z 430-->372; m/z 333-->297, respectively). Quantification was linear over the range 0.5-500ng (r(2)>0.997), precise and accurate (intra-assay RSD< or =7.2%, RME< or =8.2%; inter-assay RSD< or =15.7% RME< or =10.2%). The limit of quantification (LOQ) was 50pg injected on column, permitting reproducible analysis of RU38486 in small volumes of plasma.
authors.affiliation: Mass Spectrometry Core Laboratory and Centre for Cardiovascular Sciences, Wellcome Trust Clinical Research Facility, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, United Kingdom.
authors.forename: Natalie Z M
authors.initials: NZ
authors.lastname: Homer
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Reynolds
authors.forename: Cecilia
authors.initials: C
authors.lastname: Mattsson
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Bailey
authors.forename: Brian R
authors.initials: BR
authors.lastname: Walker
authors.forename: Ruth
authors.initials: R
authors.lastname: Andrew
mesh_terms: D000328:Adult; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006727:Hormone Antagonists / Q000097:blood / Q000737:chemistry; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D015735:Mifepristone / Q000097:blood* / Q000737:chemistry; D008970:Molecular Weight; D012997:Solvents; D013696:Temperature
chemical_list: D006727:Hormone Antagonists; D012997:Solvents; D015735:Mifepristone