This method is based on the microscale recovery procedure for total lipids by accelerated solvent extraction (ASE) developed by Eric D. Dodds and the ASET Lab ( Dodds et al. 2004, 2005a, 2005b, Beck et al. 2007). It provides a means for the determination of 70 fatty acids (FA) in tissues and lipids. This is accomplished by a solvent extraction driven by high temperature and pressure in an inert atmosphere of nitrogen. The analytes are derivatized into free fatty acids (FA) by a base catalyzed reaction and esterified to form fatty acid methyl esters (FAMEs) in an acid catalyzed reaction using the Lewis Acid boron trifloride in methanol. The analytes are injected on a gas chromatography (GC) system for separation, and are subsequently detected by a flame ionization detector (FID). Analyte identity is verified by an additional injection on a GC where the analytes are separated and identified by a mass spectrometric detector (MSD). For external verification of the method a international standard NIST 1946 is used. For a full SOP click here.

Figure 2. CC-FID Chromatogram of Harbor Seal Blubber

Beck, C.A., Rea, L.D., Iverson, S.J., Kennish, J.M., Pitcher, K.W., and Fadely, B.S. (2007): Blubber fatty acid profiles reveal regional, seasonal, age-class and sex differences in the diet of young Steller sea lions in Alaska. Marine Ecol. Prog. Ser., 338, 269-280.

Dodds, E.D., McCoy, M.R., Geldenhuys, A.,Rea, L.D., Kennish, J.M. (2004) Microscale recovery of total lipids from fish tissue by accelerated solvent extraction. J. Am. Oil. Chem. Soc. 81, 835-840.

Dodds, E.D., McCoy, M.R., Rea, L.D., and Kennish, J.M. (2005a) Proton transfer chemical ionization mass spectrometry of fatty acid methyl esters separated by gas chromatography: quantitative aspects. Eur. J. Lipid. Sci. Technol. 107, 560-564.

Dodds, E.D., McCoy, M.R., Rea, L., and Kennish, J.M. (2005b) Gas chromatographic quantification of fatty acid methyl esters: Flame ionization detection vs. electron impact mass spectrometry. Lipids, 40(4) 419-428.