Structure identification of aporphine alkaloids by on-line coupling of HPLC-NMR with loop storage

The potential of coupling HPLC separation methodology to on-line high resol ution nuclear magnetic resonance (NMR) spectroscopy has been demonstrated w ith a mixture of nine aporphine alkaloids. A loop storage procedure after s eparation has facilitated the identification of closely eluted peaks (alpha = k(2)/k(1) = 1.01 and Deltav = 0.37 min = 367 muL) These were collected o ff-line and identified by a 1D H-1 NMR spectrum. For this purpose an automa ted procedure has been implemented which includes the use of shaped pulses, multiple solvents suppression and C-13 Satellite suppression of acetonitri le.