A 31P‐NMR Study to Determine the Percent Composition of Aqueous Dispersion of Soy Lecithin

Abstract

Phospholipids are organic compounds that are comprised of a glycerol backbone, two fatty acid acyl‐chains, and a phosphate head group with various substituents. In an aqueous environment, the hydrophobic acyl‐chains minimize their contact with water by aligning to form a bi‐layered system. As the bi‐layer converges upon itself, stable bi‐layered spheres, liposomes, form. Liposomes have been used for years as a delivery agent for medical and commercial applications. In the commercial field, soy lecithin is typically used as the mixed phospholipid source to prepare liposomes. However, the concentrations of the different phospholipids can vary between providers and batches.31P NMR is to be sensitive enough to differentiate each of the specific phospholipids found in the soy lecithin mixture. Deuterated Chloroform (CDCl3) and Methanol (CH3OH) were used as the solvent system, with a mixture of Cesuim‐Ethylenediaminetetraacetic acid (Cs‐EDTA) added to further separate the signals. An internal standard of Triethyl phosphate (TEP) was used to quantify the individual concentrations of phospholipids. Utilizing 31P‐NMR, it is possible to analyze the phospholipid content of liposomes and follow the degradation of the phospholipids over time and under various conditions. This research was made possible by funding from Ingredient Innovations International and the Chemistry Department of Chemistry at The College of Wooster.