chapter  3
Chromatographic Methods for the Separation of Chlorophylls
Pages 23

M. Tswett’s separation of a plant pigment extract into colored bands of individual chlorophylls and carotenoids, due to their differential velocity on a stationary solid or liquid phase in a mobile liquid phase, marked the invention of chromatography. The detailed information on chlorophyll chromatography, focusing on more developments, is incorporated into the tables and an appendix on some special experimental techniques. The free chlorophylls are usually isolated from natural sources by solvent extraction, preferentially with acetone and/ or methanol being used. Chlorophylls are the main photosynthetic pigments of plants, most algae, and photosynthetic bacteria. All chlorophylls have comparatively narrow-banded and characteristic spectra which set them apart from most plant pigments, except the porphyrins of which they are a subclass. The natural chlorophylls and many of their derivatives are highly fluorescent in monomeric solution. Spectropolarimetric techniques and especially circular dichroism are important for stereochemical investigations of chlorophylls and for the analysis of pigment-pigment interactions.