The application of high performance liquid chromatography, coupled to nuclear magnetic resonance spectroscopy and mass spectrometry (HPLC-NMR-MS), to the characterisation of ibuprofen metabolites from human urine

The use of MPLC-NMR-MS for the detection and identification of the metabolites elf ibuprofen present in a solid phase extract of human urine is described, Gradient reversed-phase HPLC was used to separate the components present in the extract, which were then characterised by a combination of stopped-flow H-1 NMR and on line electrospray-MS, This approach led to the rapid identification of the known phase 1 human metabolites of ibuprofen, including hydroxy- and carboxy-metabolites, together with their respective glucuronide conjugates. In addition a probable artefact resulting from the dehydration of one of the side chain-hydroxylated glucuronides was also identified.