Improved recovery of fatty acid through direct transesterification without prior extraction or purification

Abstract

Methods currently in use for the quantitative measurement of fatty acids by gas-liquid chromatography after transesterification are usually lengthy and cumbersome. The technique described is a one-step reaction that is carried out in the same tube and bypasses all the extraction and purification steps. Recoveries of fatty acid and triglyceride standards (C6:0 to C24:1) were better than 96%. When the direct transesterification method was compared to the Folch extraction procedure, increases of fatty acid concentration of 11.4% and 15.8% were observed in human milk and adipose tissue, respectively. The method appears to be particularly advantageous for the recovery of the highly volatile medium chain triglycerides and there is no need to add an antioxidant to protect unsaturated lipids.