Combination of Running-Buffer-Mediated Extraction and Polyamidoamine-Dendrimer-Assisted Capillary Electrophoresis for Rapid and Sensitive Determination of Free Fatty Acids in Edible Oils

A method was developed for determining free fatty acids in edible plant oils by incorporation of running-buffer-mediated liquid–liquid extraction and polyamidoamine-dendrimer-assisted capillary electrophoresis–capacitively coupled contactless conductivity detection. The recoveries for the extraction were in the range of 90.1% and 110.3%. Addition of dendrimer to the running buffer improved the separation of fatty acids. Under the optimized buffer conditions, i.e., 3 mM pelargonic acid, 39 mM tris(hydroxymethyl)aminomethane, 30 mM polyoxyethylene 23 lauryl ether, 35% acetonitrile, 15% 2-propanol, 2.5% 1-octanol, and 300 μM polyamidoamine generation 2 at apparent pH 8.53, the 10 model fatty acids were separated in 18 min with detection limits ranging from 0.46 to 3.28 μM. The successful determination of fatty acids in real samples suggests that the method is simple, cost-effective, and easy to operate and is suitable for scanning free fatty acid in edible plant oils.