Free fatty acids (FFAs) in edible oils are one of the most frequently determined quality indices during production, storage, and marketing. In this study, a simple, stable and sensitive method for the simultaneous determination of saturated and unsaturated FFAs from edible oils using 2-(11H-benzo[a]carbazol-11-yl)-ethyl-4-methylbenzenesulphonate (BCETS) as labelling reagent with fluorescence detection has been established. FFAs are derivatized by BCETS and separated on a reversed-phase Eclipse XDB-C8 column with a gradient elution. The results indicated that all FFAs were found to be given an excellent linear response with correlation coefficients of >0.9994. The detection limits at a signal-to-noise ratio of 3 were in the range of 0.22–1.06 ng/mL. When applied to Lycium barbarum seed oils, the developed method showed good reproducibility. The effect of extraction methods including supercritical CO2 and organic solvent extraction on the FFAs composition has also been investigated. Meanwhile, this method exhibits powerful potential for the trace analysis of short- and long-chain free fatty acids from edible oils, foodstuff and other complex samples.
Fig.The 3D response surface and 2D contour plots of detection responses (peak area)
affected by the amount of BCETS (mol (BCETS)/mol (total fatty acids)), reaction temperature and reaction time.
Additional Information:
1. Author Information:Guoliang Li, Jinmao You, Yourui Suo, Cuihua Song, Zhiwei Sun, Lian Xia, Xianen Zhao, Junyou Shi.
Correspondence: jmyou6304@163.com (J. You).
2. Published : Food Chemistry, Volume 125, Issue 4, 15 April 2011, Pages 1365-1372.