Investigations on antipyrine metabolism V. Differentiation of two isomeric hydroxyantipyrine glucuronides by field desorption and fast atom bombardment mass spectrometry

Abstract

The glucuronide conjugates of the two isomeric antipyrine phase I metabolites of antipyrine in man, 4-hydroxyantipyrine and 3-hydroxymethylantipyrine have been analysed by field desorption and fast atom bombardment mass spectrometry. These isomers could be clearly distinguished on the basis of their fragmentation behaviour which was found to correlate with that observed under pyrolysis electron impact conditions.