Selective Determination of Pentafluorobenzyl Ester Derivatives of Carboxylic Acids by GC Using Microwave Plasma and Mass Selective Detection

Abstract

A highly selective, sensitive method for determination of carboxylic acids in water has been developed that is based on fluorine-selective gas chromatography (GC) detection of pentafluorobenzyl ester derivatives. The atmospheric-pressure helium microwave-induced plasma detector is well suited for fluorine-specific detection of these derivatives, which were well resolved by capillary GC and displayed a characteristic fragmentation behavior when examined by GC-mass selective detection. For demonstration purposes, a number of carboxylic acids, ranging from C₁ to C₂₀, were examined and found to be derivatized with yields greater than 90%, and a sample of creek water was examined for its carboxylic acid content.