Assay of ezlopitant, a substance P receptor antagonist, and metabolites inbiological matrices by gas chromatography with mass spectrometric detection: simultaneous analysis of a benzyl alcohol and alkene
Ae. Reed-hagen et al., Assay of ezlopitant, a substance P receptor antagonist, and metabolites inbiological matrices by gas chromatography with mass spectrometric detection: simultaneous analysis of a benzyl alcohol and alkene, J CHROMAT B, 744(2), 2000, pp. 333-343
A method for the analysis of the substance P antagonist ezlopitant and two
active metabolites in serum using solid-phase extraction followed by GC-MS
analysis is described. The linear dynamic range was 1.0 to 100 ng/ml and pr
ecision and accuracy over this range were within 15%. Upon injection of rec
onstituted sample extracts into the hot injector port of the gas chromatogr
aph, the benzyl alcohol metabolite undergoes a small amount of spontaneous
dehydration to the alkene metabolite. We have incorporated an additional he
xadeuterated internal standard of the benzyl alcohol into the assay to perm
it measurement of the extent of dehydration in each sample. This novel appr
oach should be generally applicable to the simultaneous determination of be
nzyl alcohols and corresponding alkenes by GC-MS when the possibility exist
s that the alcohol can undergo spontaneous dehydration to the alkene in the
injector port of GC instrumentation. (C) 2000 Elsevier Science B.V. All ri
ghts reserved.