A Method for Concentrating and Determining Trace Organic Compounds in the Atmosphere

Abstract : Determination of subpart-per-billion (sub-ppb) levels of volatile organic compounds in the atmosphere by flame ionization gas chromatography requires sample sizes of at least several hundred milliters of air. Cryogenic methods of concentrating trace compounds before analysis have the disadvantage of also concentrating large amounts of water, a serious problem in gas-liquid chromatography. A simple method was developed for sample collection and concentration using porous polymer adsorbants with the unique properties of high capacity for retention of organic compounds and minimal capacity for retention of water. This technique was used to determine sub-ppb levels of volatile organic compounds in a typical rural atmosphere. Probable sources of these organic compounds were vehicle exhaust, biological processes, natural gas leaks, and industrial chemicals.