Analysis of free fatty acids in Notopterygium forbesii Boiss by a novel HPLC method with fluorescence detection.

A new labeling reagent for fatty acids, 1-(9H-carbazol-9-yl) propan-2-yl-methanesulfonate (CPMS), has been synthesized and successfully applied to the HPLC determination of fatty acids in traditional Chinese herb Notopterygium forbesii Boiss. The reaction of CPMS with fatty acids could proceed easily and quickly in the presence of K(2)CO(3) catalyst within 30 min. The derivatives exhibit excellent fluorescence property with excitation and emission wavelengths of 293 nm and 360 nm respectively. The 34 derivatives of fatty acids were separated on a BDS C8 reversed-phase column with gradient elution. Good linear correlations were observed for all fatty acids with correlation coefficients of >0.996. The detection limits at a signal-to-noise ratio of 3 were in the range 0.032-0.312 μg g(-1). Free fatty acids in the roots, stem, leaves and petioles of N. forbesii Boiss from different places were analyzed by the developed method. This is the first time that the fatty acids composition of N. forbesii Boiss has been reported. This method also shows powerful potential for the trace analysis of fatty acids or other carboxylic acids from complex samples.