|Emken, Edward - USDA, RETIRED|
Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 1998
Publication Date: N/A
Technical Abstract: Our studies of the absorption and metabolism of triglyceride (TG) positional isomers in human and animal models required the analysis of isolated triglyceride samples by lipase. The triglycerides of blood and isolated blood fractions; native lard and randomized lard; and soybean oil were extracted and treated with lipase. The 2 monoglyceride (MG) fractions swere separated from TG, free fatty acids (FFA) and diglycerides (DG) on a Zymark Benchmate workstation by silica solid phase extraction (SPE, 3 mL) columns. Thin layer chromatography (TLC) was used to verify the completeness of the MG separations. Average recoveries (ca. 40%) of the MG in >95% purity were consistent with published results. The isolated MG were manually converted to methyl esters and the workstation was used to isolate the methyl ester fractions from the reaction mixtures. The impacts of solvent volumes and sample size on MG/ methyl ester recoveries was studied. Ester recoveries for the workstation were dependent on the initial substrates, but generally exceeded >90%, compared with manual extraction yields of 95-98%. Fatty acid compositions of ester samples isolated by robotic methods agreed within 1-2% with samples isolated by non-robotic means.