Symmetry C18 column: a better choice for the analysis of indole alkaloids of Catharanthus roseus.

By virtue of the different elution patterns of vindoline, catharanthine, vincristine and vinblastine present in the leaves of Catharanthus roseus plants, a Symmetry C18 column provided a better resolution for all of these compounds as compared with other C18 columns. The binary gradient system with a linear gradient profile, employed in a method developed using a Symmetry C18 column, gave excellent peak symmetry, resolution and reproducibility. Detection was performed at 220 nm which presented better absorptivity for these indole alkaloids giving a minimum detection limit of 0.5 microgram. Photodiode array detection was used to determine the homogeneity and purity of each compound. The described analysis is rapid and economical to perform as small amounts of solvent are consumed per analysis, and the method will find application where a large number of samples are to be analysed as, for example, in crop improvement studies where plants need to be selected regularly on the basis of alkaloid production.