Abstract
Free fatty acids were determined by high performance liquid chromatography after derivatization with monodansyl Cadaverine (MDC) at room temperature for 15min in the presence of diethyl phosphorocyanidate as a coupling reagent. The fluorescence properties (λex340nm, λem 518nm) of MDC-arachidic acid (C20:0) were identical to those of dansyl alanine. The MDC derivatives of saturated and unsaturated fatty acids were completely separated within 50min by gradient elution on a TSK-gel 80TM ODS column. When fluorometrically detected, the detection limits (S/N=3) of fatty acid were below 100fmol. The calibration curves passed through the origin and gave good linearity in the range from 5 to 200pmol. The method was successfully applied to the determination of fatty acids in the rabbit plasma. This method would be quite useful for the analysis of various biological samples for thermolabile carboxylic acids, since it requires no heating procedure.
