INVESTIGATION OF THE FEASIBILITY OF DIRECTLY-COUPLED HPLC-NMR WITH H-2 DETECTION WITH APPLICATION TO THE METABOLISM OF N-DIMETHYLFORMAMIDE-D(7)

The use of H-2 NMR spectroscopy as a detector for HPLC has been invest igated using the continuous flow method in which rat urine containing metabolites of N-dimethylformamide-d(7) was employed as a test case. T hree xenobiotic-related species, including DMF-d(7) itself, were detec ted. It is shown that for small molecules which give relatively sharp H-2 NMR resonances, H-2 HPLC-NMR spectroscopy is a feasible technique. For larger molecules, the resulting broad fines are likely to preclud e the determination of detailed structural information. However, exten sion of the approach is possible by the use of selectively H-2-labelle d xenobiotics to determine HPLC retention times of metabolites with co ntinuous-flow H-2 NMR spectroscopy detection, followed by stop-flow H- 1 HPLC-NMR spectroscopy for structural characterisation. (C) 1997 Else vier Science B.V.