FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY OF SUCROSE MONOCAPRATE AND SUCROSE MONOLAURATE

Fast Atom Bombardment (FAB) ionization of sucrose monocaprate and sucrose monolaurate in the presence of Na+ ions shows the formation of both [M + Na]+ and [M - H]- ions. The [M + Na]+ ions undergo charge-remote fragmentations when collisionally activated st high translational energy. These charge-remote fragmentations are useful for the structural determination of the acylic part of the glycolipid. In the negative ion mode both sucrose esters yield anions which can be attributed to the saccharide and lipid components of these glycolipids. Structural characterization of the fatty acid can be achieved as the released carboxylate anions undergo charge-remote fragmentations that are consistent with the ion chemistry of [M - H]- anions from FAB-ionized free fatty acids.