Reversed-phase ion-pair liquid chromatographic procedure for the simultaneous analysis of S-adenosylmethionine, its metabolites and the natural polyamines

A method using reversed-phase ion-pair liquid chromatography with dual detection was developed for the simultaneous determination of the S-adenosylmethionine (SAM) analogues and the natural polyamines. The separation is obtained with a gradient elution and by adjusting the concentration of octanesulfonic acid used as ion-pairing agent, the ionic strength of the eluent, the pH and the acetonitrile content of the eluents. The SAM analogues are analyzed by UV detection at 254 nm and the polyamines by fluorescence detection after post-column derivatization with o-phthalaldehyde. The method allows the determination of the SAM analogues and the polyamines in one single run by direct injection of tissue extracts. The procedure is applied to the study in rats and in hepatoma tissue culture cells of the biochemical effects of α-difluoromethylornithine, a potent enzyme-activated irreversible inhibitor of ornithine decarboxylase.