An infrared spectroscopy study of lipid adsorption from hexane onto an acid-activated bleaching clay
by Adhikari, C.; Proctor, A.; Blyholder, G. D.
The mode of adsorption of oleic acid (OA) (0.05 M), triglyceride (TG) (0.05 M) and phosphatidylcholine (PC) (0.5 mM) from hexane solution onto 0.5 g of an acid-activated bleaching clay was investigated using diffuse reflectance Fourier transform infrared spectroscopy. OA was mostly weakly adsorbed by bound water, with some OA adsorbed to silanol sites through carboxyl carbonyl groups. TG was hydrogen-bonded to surface silanol groups through ester carbonyl groups. The CH2 stretches indicated that TG was oriented perpendicular or at an angle to the surface. PC phosphate groups were bound by the surface moisture with little interaction with silanol groups. The adsorption mechanism of these lipids contrasts with the adsorption of carotenoid and chlorophyll under the same conditions. These pigments are bound by chemisorption, with catalytic modification often occurring before adsorption.
- Journal
- Journal of the American Oil Chemists Society
- Volume
- 74
- Issue
- 10
- Year
- 1997
- Start Page
- 1265-1268
- URL
- https://dx.doi.org/10.1007/s11746-997-0055-7
- ISBN/ISSN
- 1558-9331; 0003-021X
- DOI
- 10.1007/s11746-997-0055-7