SOY FATTY-ACID OXIDATION WITH SODIUM-HYPOCHLORITE MONITORED BY NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

The oxidation process of soy fatty acids by sodium hypochlorite with r uthenium trichloride catalyst was examined at different temperatures a nd active chlorine:fatty acid molar ratios. H-1 and C-13 distortionles s enhancement by polarized transfer nuclear magnetic resonance (NMR) s pectroscopy techniques were used to monitor oxidation of the double bo nds in unsaturated lipids by measuring the peak integration ratio of d ouble-bond peaks:methylene-methyl peaks. This NMR monitoring technique proved to be an excellent means to quantify double-bond reactions. Ca s chromatography-mass spectrometry was used to identify mono-and diaci d products, separated by hexane/methylene chloride extraction, as well as other oxidation products. While the presence of ruthenium catalyst in creased the initial rate of oxidation, it also catalyzed the decom position of hypochlorite, decreasing the available reactive chlorine, resulting in a delay in complete oxidation. A 9:1 molar ratio of activ e chlorine to fatty acids completely oxidized all double bonds of soy fatty acids. However, the yield of low-molecular-weight monoacid oxida tion products was only 17%, indicating the probable formation of hydro xy fatty acids.