Multicomponent analysis of encapsulated marine oil supplements using high-resolution H-1 and C-13 NMR techniques

Multicomponent high-resolution H-1 and C-13 NMR analysis has been employed for the purpose of detecting and quantifying a wide range of fatty acids (as triacylglycerols or otherwise) in encapsulated marine cod liver oil supplements. The H-1 NMR technique provided quantitative data regarding the docosahexaenoic acid content of these products, which serves as a valuable index of fish oil quality, and a combination of both H-1 and C-13 spectroscopies permitted the analysis of many further components therein, including sn-1 monoacylglycerols, sn-1,2 and -1,3 diacylglycerol adducts, together with a range of minor components, such as trans-fatty acids, free glycerol and cholesterol, and added vitamins A and E. The identities of each of the above agents were confirmed by the application of two-dimensional H-1-H-1 spectroscopies. The NMR techniques employed also uniquely permitted determinations of the content of non-acylglycerol forms of highly unsaturated (or other) fatty acids in these products (i.e., ethyl esters), and therefore served as a means of distinguishing natural sources of cod liver oils from those subjected to chemical modification to and/ or supplementation with synthetic derivatives such as ethyl docosahexaenoate or eicosopentaenoate. The analytical significance and putative health effects of the results acquired are discussed.-Siddiqui, N., J. Sim, C. J. L. Silwood, H. Toms, R. A. Iles, and M. Grootveld. Multicomponent analysis of encapsulated marine oil supplements using high-resolution H-1 and C-13 NMR techniques.