SEPARATION OF HIGH-MOLECULAR-MASS CARRAGEENAN POLYSACCHARIDES BY CAPILLARY-ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION

A method is described for the separation and quantitation of unhydroly zed carrageenan polysaccharides (molecular mass approx. 3.10(5) rel. m ol mass) by capillary electrophoresis. Various carrageenan samples wer e first derivatized with the fluorescent reagent, trisodium 8-aminopyr ene-1,3,6-trisulfonate (APTS), in both laboratory and commercial blend samples. Microcentrifuge filters (3.10(4) rel. mel. mass) were then e mployed to separate derivatized samples into low (eluate) and high (re tentate) molecular mass fractions which could each be assayed by CE wi th laser-induced fluorescence detection. Eluate fractions contained sm all amounts of kappa and iota species which could be efficiently separ ated by capillary zone electrophoresis (CZE) using a buffer with an an ti-convective additive. Separation of species contained in the retenta te fraction (kappa, iota, lambda) could be achieved in under 5 min by CZE using a citrate buffer, pH 3.0. The influence of the pre-filtratio n step, field strength and temperature on peak efficiency and resoluti on are studied. Quantitative aspects are evaluated and the method then applied to real commercial samples of food additive mixtures. (C) 199 8 Published by Elsevier Science B.V.