ANALYSIS OF UNDERIVATIZED C-12-C18 FATTY-ACIDS BY REVERSED-PHASE ION-PAIR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH CONDUCTIVITY DETECTION

A rapid, simple and precise reversed-phase ion-pair high-performance liquid chromatographic method is described for the separation and determination of underivatized fatty acids (C-12-C18) using a conductivity detector. Baseline separation of eight fatty acid standards was achieved on an octadecylsilyl column using isocratic elution with a methanol-5 mM tetrabutylammonium mobile phase. The method was successfully applied to the determination both of an anionic surfactant and of free fatty acids extracted from etiolated wheat shoots. The detection limit of margaric acid was ca. 2 ng at a signal-to-noise ratio of 3.