Development and characterization of an improved silicic acid‐KOH arrestant column for routine quantitative isolation of free fatty acids

Abstract

An improved silicic acid‐KOH arrestant column method for the quantitative isolation of free fatty acids (FFA) is described. The method involves preparation of samples in acidified silicic acid caps that are placed directly above alkaline arrestant column portions in glass Chromatographic tubes. Neutral lipids are eluted with solvents whereas FFA are stopped as K‐salts. FFA are recovered by elution with formic acid‐containing solvents. The accuracy and reproduci‐bility of existing methods were greatly improved by minimizing and stabilizing the extent of alkali‐induced glyceride hydrolysis. The improved method is suitable for adaptation to a wide variety of food products and biological systems.

Free fatty acids quantification in dairy products

“…Due to their strongly alkaline nature, hydrolysis of glycerides is known to occur if silicic acid columns/KOH (Stark et al . ; Woo and Lindsay ), and ion exchange resins (Stark et al . ) are used and can result in an overestimation of FFA levels.…”