Determination of trace amounts of carboxylic acids in ambient air by capillary gas chromatography - mass spectrometry

A method for the determination of organic acids in ambient air using an ion-exchange resin in a bifunctional manner is presented. The ion-exchange resin is used as an adsorbent for sampling and subsequently as catalyst for the methylation of the adsorbed acids by methylformate. The methyl esters are analysed by gas chromatography or gas chromatography-mass spectrometry. This method can be used to monitor workplace atmospheres and to analyse other ambient air samples.