Packed column supercritical fluid chromatography of sesquiterpene lactones with different carbon skeletons

The analyses of eighteen different C-skeleton sesquiterpene lactone (SL) standards and of extracts of Cardus benedictus L. and Artemisia umbelliformis Lam. were carried out by SFC-UV. SLs of the groups of germacranolides, guaianolides, eudesmanolides, seco-eudesmanolides and helenanolides were investigated. Different stationary phases, different densities, several modifiers and modifier programmes were applied in order to optimize their separation. A CN stationary phase with MeOH-water (95:5) as modifier for supercritical CO2 was the most successful combination in the separation of the SLs investigated. (C) 1997 Elsevier Science B.V.