SEPARATION OF COLOR PIGMENTS OF CAPSICUM-ANNUUM BY ADSORPTION AND REVERSED-PHASE THIN-LAYER CHROMATOGRAPHY

Silica gel, aluminum oxide, cellulose, diatomaceous earth, 1:1 silica gel - diatomaceous earth, polyamide, cyano, diol, and amino plates hav e been tested for their capacity to separate the color pigments of pap rika (Capsicum annuum) by both adsorption and reversed phase TLC. In a dsorption chromatography some pigments were generally left at the orig in even by the strongest eluents, limiting the application of this tec hnique. The best adsorption TLC separations were achieved on aluminum oxide layers developed with n-hexane - chloroform mixtures. In reverse d phase chromatography only acetone - water and tetrahydrofuran - wate r mixtures were able to transport all the color pigments on cyano plat es and on supports prepared by impregnation of cellulose, silica, and diatomaceous earth. The best separations were achieved with eluents co mprising mixtures of tetrahydrofuran, acetone, and water or acetone an d water on layers prepared from impregnated diatomaceous earth. Becaus e of large differences in the lipophilicities of the pigments, each fr action could not be separated by a single development.