Advances in Trapping Procedures for Organic Indoor Pollutants

Abstract

In indoor air research the trace levels and the diversity of the airborne organics in the air must be considered when choosing a method of trapping and analysis. The choice of trapping method can greatly bias the results that will be obtained. The primary methodologies used for trapping of indoor pollutants include trapping on solid adsorbents with subsequent solvent or thermal desorption, grab sample collection in Summa-polished canisters (SIS; Moscow, ID) with trapping or cryofocusing prior to analysis, or direct analysis of the gaseous sample. Although it is the most widely used technique, trapping, or collection on solid adsorbents, can result in considerable compound bias due to the nature of the adsorbents used. This methodology combined with thermal desorption is most useful for nonpolar C4-C30 compounds, depending on the solid adsorbents used for trapping and collection. Grab sample collection in Summa-polished canisters is primarily useful for nonpolar midrange boiling compounds. Direct gaseous analysis is particularly useful for polar compounds but can suffer severely from insufficient sensitivity.