Graeme B. Scarfe, Ian D. Wilson, Manfred Spraul, Martin Hofmann, Ulrich Braumann, John C. Lindon and Jeremy K. Nicholson
Directly coupled HPLC–NMR–MS was used to identify the major urinary metabolite of 2-bromo-4-trifluoromethylaniline in the rat as the sulfate conjugate of 2-bromo-4-trifluoromethyl-6-hydroxyaniline. This metabolite could not have been fully characterised using HPLC–NMR or HPLC–MS alone as the sulfate group is ‘NMR silent’ and MS would not have enabled the position of substitution on the aromatic ring to have been assigned. The need to carefully select HPLC solvents for directly coupled HPLC–NMR–MS so that NMR and MS data can both be obtained is also shown.