Determination of Free Fatty Acids from Soil and Bryophyte by High-performance Liquid Chromatography Mass Spectrum (HPLC/MS) with Fluorescence Detection

A novel fluorescence reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl-toluene-4-sulfonate (BDBETS) was synthesized, and using which as pre-column derivatization reagent ,19 fatty acids were derivatized optimally. On a reversed-phased Eclipse XDB-C_8 column, 19 fatty acid derivatives were separated at baseline and analysized quantificationally. Fluorescent detection excitation and emission wavelengths were set at λ_(ex) 333 nm, λ_(em)390 nm, respectively. Correlation coefficients for fatty acid derivatives are 0.9989, and detection limits (at signal-to-noise of 3∶1) are 24.8～(80.37) fmol. Qualificative analysis of free fatty acids from soil and bryophyte samples was obtained on the basis of APCI source at positive model detection. The established method is sensitive and reproducible for the determination of free fatty acids from real samples with satisfactory results.