TEMPERATURE-DEPENDENCE OF THE CAPACITY FACTORS OF ALKALOIDS IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY

The temperature dependence of capacity factors of the alkaloids from Chelidonium majus L. in reversed-phase liquid chromatography is investigated. When the surface of the stationary phase is deactivated, for instance by potassium iodide, two groups of van’t Hoff plots for the alkaloids are found, namely those of the tertiary alkaloids with low basicity and those of the strongly basic tertiary and quaternary alkaloids. This behavior is interpreted in terms of differrent retention mechanisms for the two groups depending on the basicity of the eluites. © Oxford University Press 1992.