Determination of acidic and basic species by headspace gas chromatography

This paper reported a novel headspace gas chromatographic (GC) technique on quantification of acidic and basic species. It is based on an acid-base reaction between the measured species and bicarbonate in an aqueous solution, which generates carbon dioxide in a closed headspace sample vial. By operating at 60 °C, carbon dioxide is completely released to the headspace and thus can be measured by GC with a thermal conductivity detector. Bicarbonate concentrations of 0.030 and 0.0025 mol/L are recommended for general applications and very small species content, respectively. This method is able to accurately measure small sample sizes (down to few milligrams or microliters). The present method is simple, accurate, and automatic.