O‐etherification between glycerol and glycerol monooleate—demonstration of formation of diglycerol monooleate and triglycerol monooleate by fast atom bombardment‐mass spectroscopy and 13C nuclear magnetic resonance

Abstract

AbstractTo prepare glycerol monooleate, we reacted glycerol with oleic acid in the presence of a K1411 sulfonic acid resin in the H+ form. We utilized glycerol monooleate as an emulsifying agent, as it is a nonionic surfactant that is compatible with the initially biphasic reaction medium. If the expected product does not form, small amounts of a highly polar compound are produced. Both diglycerol monooleate and triglycerol monooleate were isolated by preparative chromatography on a silica column (hexane/chloroform/acetone, 25∶50∶50), and were formally identified by fast atom bombardment (FAB)‐mass spectroscopy in positive mode. The products were polyglycerol monoesters. The nature of the products was confirmed by the use of different FAB matrices with or without cationization by alkali metals. The structure of the product was then confirmed by 13C nuclear magnetic resonance. we can now propose a new method of polyglycerol ester preparation that yields interesting nonionic emulsifying agents.