title: Determination of an acetylcholinesterase inhibitor, MDL 73745, in dog plasma and urine by combined gas chromatography/negative ion chemical ionization mass spectrometry.
abstract: A highly sensitive and specific assay has been developed for the determination of MDL 73745 [2,2,2-trifluoro-1-(3-trimethylsilyl-phenyl) ethanone] (I) and the internal standard (MDL 74398) at the nanomolar level in dog plasma and urine by gas chromatography/mass spectrometry. After a single-step extraction process, an aliquot was directly injected onto the gas chromatograph column. The mass spectrometer was run in the negative ion chemical ionization mode with ammonia as reagent gas, and was set to monitor the abundant M-. ion at m/z 246 of both compounds. The method yielded a linear response over the concentration range 0.1-10 pmol 100 microliters -1 plasma or urine. Within-day reproducibility at a concentration of 0.25, 1 and 5 pmol 100 microliters -1 plasma was 8.6%, 1.0% and 1.0%, respectively. The method was applied to the determination of I in plasma and urine after administration of 1 mg kg-1 i.v. and 10 mg kg-1 p.o. to dogs.
authors.affiliation: Marion Merrell Dow Research and Development Center, Department of Clinica Biochemistry and Drug Metabolism, Strasbourg, France.
authors.forename: B D
authors.initials: BD
authors.lastname: Dulery
authors.forename: N
authors.initials: N
authors.lastname: Le Henanf
authors.forename: J
authors.initials: J
authors.lastname: Dow
authors.forename: K D
authors.initials: KD
authors.lastname: Haegele
mesh_terms: D000098:Acetophenones / Q000032:analysis* / Q000097:blood / Q000652:urine; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000097:blood / Q000652:urine; D004285:Dogs; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008297:Male; D014297:Trimethylsilyl Compounds / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D000098:Acetophenones; D002800:Cholinesterase Inhibitors; D014297:Trimethylsilyl Compounds; C082826:zifrosilone