GIC FID and GC MS (Fatty Acids)
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.
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