A number of reports on the analysis of C19-diterpenoid alkaloids by high performance liquid chromatography (HPLC) have appeared in recent years1-3. Hikino and co-workers1,2 were the first to study the separation and quantitation of certain aconitum alkaloids. They used an ODS chemically bonded silica column (stationary phase) and phosphate buffer (pH 2.7)-tetrahydrofuran (mobile phase) to achieve a complete separation of ten aconitine type alkaloids. Later Kitagawa et al.3 reported the analysis of several aconitum alkaloids including a few lipo-alkaloids. As part of our studies in developing efficient and rapid methods for the analysis of diterpenoid alkaloids4,5 we are interested in determining the content of C19-diterpenoid alkaloids from crude extracts of Delphinium and Aconitium species. Attempts to analyse a mixture of 3-acetylaconitine (1), aconitine (2), mesaconitine (3), deoxyaconitine (4), 8-O-methyl-14-benzoylaconine (5), 14-benzoylaconine (6) and delphinine (7) under Hikino's chromatographic conditions1 [a C18 chemically bonded silica column and phosphate buffer (pH 2.6)-tetrahydrofuran (4:1)] were not satisfactory. In our hands, this assay method suffered from a lack of resolution and tailing of peaks, perhaps because of the nature of the C18 phase used. This problem led us to develop a different system involving the use of a simple mobile phase, consisting of 2 mM ammonium carbonate and tetrahydrofuran. A simple chromatographic system for the separation of certain groups of C19-diterpenoid alkaloids is described. A significant separation was achieved for the permanganate oxidation products of aconitine. This system, with minor modifications, can be extended to study the alkaloidal content of Aconitum and Delphinium species.