Superheated deuterium oxide reversed-phase chromatography coupled to proton nuclear magnetic resonance spectroscopy

The on-line coupling of superheated deuterium oxide reversed-phase liquid chromatography and NMR spectroscopy overcomes many of the problems faced by conventional HPLC-NMR systems and provides a new method for the examination of moderately polar organic compounds. Samples of salicylamide and barbiturates were separated on a polystyrene-divinylbenzene (PS-DVB) column and transferred to a NMR spectrometer for on-line or stop-flow detection. This approach enables isothermal and temperature gradient reversed-phase HPLC-NMR spectroscopy to be readily carried out without the use of deuterated organic solvents. Unlike supercritical fluid chromatography-NMR spectroscopy, the method can be carried out with a low pressure HPLC-NMR probe.