Analysis of almitrine and its metabolites in plasma using on-line fast atom bombardment liquid chromatography/mass spectrometry.

To validate a recently developed liquid chromatography/ultraviolet (LC/UV) method in a pharmacokinetic study of Vectarion (almitrine) where the unchanged drug, its five metabolites and an internal standard are analysed, on-line fast atom bombardment liquid chromatography/mass spectrometry (FAB LC/MS) with a moving belt interface has been used. Since the liquid chromatographic conditions required the use of perchloric acid FAB was chosen as ionization mode for the involatile perchlorates formed in the liquid chromatographic process. The use of FAB LC/MS allows the detection of the protonated molecular ions of all the components in the mixture. Furthermore, all the compounds show an intense peak at m/z 203, presenting a liquid chromatographic profile which is very similar to the profile obtained with UV detection.