Separation and identification of vitamin A acetate isomers by supercritical fluid chromatography H-1 NMR coupling

Unlike HPLC-NMR coupling, the combination of supercritical fluid chromatography (SFC) with NMR spectroscopy is not yet a routine method, but the feasibility of this coupling technique has already been demonstrated with synthetic mixtures. In this paper the first real life application is presented and the potential of this new method is shown. A mixture of five cis/trans isomers of vitamin A acetate is separated by SFC using supercritical CO2 as eluent. Therefore no solvent signal suppression is necessary and the unrestricted observation of the whole spectral range is possible, contrary to the HPLC separation in n-heptane, where in the aliphatic region almost 2 ppm of the H-1 NMR spectrum are affected by the suppression technique.