Synthesis and gas chromatography of fluorinated ester derivatives of organic acids

A method is described for the gas-liquid partition chromatographic analysis of organic acids as their 2,2,2-trlfluoroethyl esters. This procedure, utilizing trifluoroeacetio anhydride for the preparation of the ester derivatives, has been evaluated and found to be simple, rapid and quantitative. Various 2,2,2-trifluoroethyl esters have been prepared and characterized by infrared and nuclear magnetic resonance spectroscopy. Relative retention times comparing the fluoro esters with the respective ethyl esters have been obtained. Various stationary phases have been evaluated with respect to column efficiency, carrier gas flow rates and column temperatures. Shown quantities of acids have been analyzed with quantitative recoveries.