FATTY-ACID DISTRIBUTION OF FATS, OILS AND SOAPS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITHOUT DERIVATIZATION

A high-performance liquid chromatography (HPLC) procedure without derivatization was developed for quantitating fatty acid components of various soap related fats and oils, as well as for the direct quantitation of fatty acids from soap. The fatty acids are detected by refractive index after isocratic reverse-phase chromatography. The method has been developed with radial compression and stainless-steel column technology. The triglycerides are saponified and acid-hydrolyzed into fatty acids, and they are dissolved in a solvent and injected. The soaps are dissolved in methanol and injected into the HPLC, where they are acid-hydrolyzed directly on the column by an acid-modified mobile phase. The total run time after injection is approximately 20 min, with quantitation performed on an NEC Powermate(R) computer driven by PE/Nelson Analytical Software. The typical carbon chains analyzed are from C6 to C20.