Performance of a Tenax GC collector for collection and analysis of volatile organic compounds in air

Abstract

A new type of collector-injector using Tenax GC adsorbent was developed for collection and analysis of tracelevel volatile organic compounds in air. The collector is simple shape made of 6mm o.d.× 16cm glass tube, and desorption is carried out in an airtight desorption chamber directly connected with a gas chromatograph. Performance of the collector was tested under conditions relevant to field sampling, compared with a needle type collector which is commercially available as a styrene collector.
Background of desorption chromatogram of usual collectors is influenced by contamination during storage period before and after sampling in field survey, but the influence of contamination on desorption chromatogram by this method was negligible in case of measuring ppb-level organic pollutants during 4 days storage period, while the needle type collectors gave maximum 6 ppb error in measuring 1 liter air sample. Peaks of desorption chromatogram by this method were not so broadened, gas chromatographic separation is maintained. Separabilities of p-and m-xylene (concentration ratio 1: 1) were 1.17, 1.02, and 0.84 in direct injection by a syringe, this method, and the needle collector, respectively.