The use of low-energy collisionally activated dissociation negative-ion tandem mass spectrometry for the characterization of dog and human urinary metabolites of the drug BW 1370U87.

L C Taylor, R L Johnson, L St John-Williams, T Johnson, S Y Chang

Index: Rapid Commun. Mass Spectrom. 8(3) , 265-73, (1994)

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Abstract

Liquid chromatography (LC) combined with atmospheric pressure chemical ionization mass spectrometry was used to identify phase I and II metabolites of the drug BW 1370U87 in dog and human urine. Additional analysis of individual high-performance liquid chromatograph fractions collected from dog urine by combined gas chromatography/mass spectrometry identified one metabolite which was not detected by LC/MS methods. Using negative-ion LC/MS, the majority of BW 1370U87 metabolites in human urine were identified as glucuronic acid conjugates of phase I oxidative metabolites. The negative-ion fragmentation produced by low-energy collisionally activated decomposition (CAD), studied by tandem mass spectrometry experiments, confirmed that these compounds were drug-related and allowed metabolite structures to be assigned. Product-ion spectra of the metabolites were dominated by the loss of neutral molecules from even-electron deprotonated [M-H]- ions.