Determination of 17-monochloroacetylajmaline and its metabolite in plasma by TLC fluorescence detection

A sensitive and specific method is described for the determination of 17-monochloroacetylajmaline (I) and its metabolite, ajmaline (II), in plasma. Method specificity is accomplished by combining an ion-pair extraction with chromatography followed by development and utilization of reaction product fluorescence of the isolated species on silica gel. Recovery of I and II added to plasma or water averaged 70%. The major loss in the assay resulted during a solvent evaporation step and was reproducible over the concentration interval studied. The limit of detectability for I is 0.06 mu-g/2 ml of plasma. The method was used to determine plasma levels of I and II in the dog following a dose of 10 mg/kg iv of I.