Separation and identification of astaxanthin esters and chlorophylls in Haematococcus lacustris by HPLC

An isocratic reverse-phase high performance liquid chromatographic method was developed for the separation of carotenoids and chlorophylls from extracts of Haematococcus lacustris. Astaxanthin monoesters are the principal carotenoids in Haematococcus lacustris. Five astaxanthin monoesters, which accounted for 79% of the total carotenoids, were identified and the individual contents were determined by HPLC to be 7.3, 24.9, 6.1, 49.4 and 12.3% of the total astaxanthin monoesters, respectively. The maximum absorption wavelengths of the five astaxanthin monoesters in the mobile phase were all 479 nm, and that of free astaxanthin, the main saponification product of the astaxanthin esters, was 478 nm.