Journal of Lipid Research, Vol 27, 452-456, Copyright © 1986 by Lipid Research, Inc.
Transesterification of phospholipids or triglycerides to fatty acid benzyl esters with simultaneous methylation of free fatty acids for gas- liquid chromatographic analysis
FJ van Kuijk, DW Thomas, JP Konopelski and EA Dratz
A novel method is presented for transesterification of fatty acid esters in
phospholipids and triglycerides to benzyl esters while simultaneously
recovering free fatty acids as methyl esters. Transesterification is
catalyzed by 0.2 M (m-trifluoromethyl phenyl)trimethyl ammonium hydroxide
in methylene chloride, 10% (v/v) benzyl alcohol, and 1% (w/v) potassium
tert-butoxide, and is complete in 30 min at room temperature. Methyl esters
of all common fatty acids separate from the benzyl esters formed from
phospholipids. This method has broad utility and is applicable to the
formation of esters optimized for detection by absorbance or fluorescence
(high performance liquid chromatography), electron capture (gas-liquid
chromatography), or negative ion chemical ionization (gas-liquid
chromatography-mass spectrometry).