RETENTION OF SOME GLUCOSINOLATES IN ANION-EXCHANGE CHROMATOGRAPHY .1. QUALITATIVE STUDY ON A SILICA-TRIALKYLAMMONIUM EXCHANGER

The retention and separation of glucosinolates, as organic anions, were studied on a silica-based strong anion exchanger under isocratic elution conditions. All glucosinolates carry the same functional ionic group (-OSO3-), however they do not have the same retention in anion exchange chromatography. The plots of capacity factors of organic anions versus the reciprocal of eluent ion concentration show good linearity. From the slope and y-intercept data the major retention mechanisms are interpreted as ion exchange, and reversed-phase interactions. The effects of nature and concentration of the eluent ion and the influence of organic modifier addition to the aqueous buffered mobile phase are also investigated. Direct and indirect UV detection were used. Our results open the way for the development of new systems for intact glucosinolate analysis which are easier to use than the present ion-pairing chromatographic method.