title: Directly coupled CZE-NMR and CEC-NMR spectroscopy for metabolite analysis: paracetamol metabolites in human urine.
abstract: Direct coupling of NMR spectroscopic detection with both capillary zone electrophoresis (CZE) and capillary electrochromatography (CEC) was applied to the separation of metabolites of the drug paracetamol in an extract of human urine. Continuous-flow CZE-NMR and CEC-NMR allowed the detection of the major metabolites, the glucuronide and sulfate conjugates of the drug and the endogenous material hippurate. Identification of these substances was achieved by examination of individual rows of the NMR chromatogram and this also gave estimates of the detection limits. For CEC-NMR, spectra were also obtained in the stopped-flow mode including a two-dimensional TOCSY NMR experiment which afforded confirmatory evidence for paracetamol glucuronide. Characterisation of drug metabolites using NMR spectroscopy is therefore possible with nanolitre sample volumes.
authors.affiliation: Organisches Institut, Universität Tübingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schewitz
authors.forename: P
authors.initials: P
authors.lastname: Gfrörer
authors.forename: K
authors.initials: K
authors.lastname: Pusecker
authors.forename: L H
authors.initials: LH
authors.lastname: Tseng
authors.forename: K
authors.initials: K
authors.lastname: Albert
authors.forename: E
authors.initials: E
authors.lastname: Bayer
authors.forename: I D
authors.initials: ID
authors.lastname: Wilson
authors.forename: N J
authors.initials: NJ
authors.lastname: Bailey
authors.forename: G B
authors.initials: GB
authors.lastname: Scarfe
authors.forename: J K
authors.initials: JK
authors.lastname: Nicholson
authors.forename: J C
authors.initials: JC
authors.lastname: Lindon
mesh_terms: D000082:Acetaminophen / Q000737:chemistry / Q000378:metabolism* / Q000652:urine; D018712:Analgesics, Non-Narcotic / Q000737:chemistry / Q000378:metabolism* / Q000652:urine; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen