HPLC DETERMINATION OF UNDERIVATIZED FATTY-ACIDS SAPONIFIED AT 37-DEGREES-C ANALYSIS OF FATTY-ACIDS IN OILS AND TISSUES

The present study was undertaken to establish a simple and appropriate method for fatty acids determination where samples are not submitted to high temperatures during the preparative and quantification process es. We describe an alternative method in which two techniques develope d separately were combined: lipids saponification at low temperature a nd underivatized fatty acids quantification by HPLC (high performance liquid chromatography). Total lipids fraction was extracted from oils and rat tissues using the Folch method. Lipids were saponified at 37 d egrees C for 2 hours and extracted with hexane. Fatty acids were separ ated in a reverse-phase column (C-8-Shimadzu) and identified by a refr active index detector (RID-6A-Shimadzu). Fatty acid. composition of oi ls (soybean oil, coconut fat and cocoa butter) and rat tissues (spleen and thymus) was determined. The analysis of fatty acids using this me thod was reproducible and the retention time, fatty acid recovery, min imal detection limit were compared to gas chromatography. The advantag e of this method is that during handling and detection, fatty acids ar e not exposed to high temperatures, decreasing the possibility of its oxidation and racemization. Therefore, this method is recommended when fatty acids recovery is required.