title: Determination of ethambutol in plasma using selected ion monitoring.
abstract: The determination of ethambutol in plasma is described. Using ethambutol-d4 as an internal standard, ethambutol and the internal standard were extracted with chloroform under alkaline conditions, and converted into their trifluoroacetyl derivatives with trifluoroacetic anhydride in benzene-pyridine (4:1). Selected ion monitoring was carried out by monitoring the peaks at m/z 294 and 296 corresponding to the fragment ion [M/2]+ of the derivatives. Ethambutol was determined by use of the peak height ratio of the peak at m/z 294 against that at m/z 296. The method was utilized for studying the bioavailability and pharmacokinetics of the drug.
mesh_terms: D000818:Animals; D001682:Biological Availability; D003903:Deuterium; D004285:Dogs; D004977:Ethambutol / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007477:Ions; D007700:Kinetics; D008297:Male; D012015:Reference Standards
chemical_list: D007477:Ions; D004977:Ethambutol; D003903:Deuterium