HIGH-VOLUME AIR SAMPLER FOR PARTICLE AND GAS SAMPLING .1. DESIGN AND GAS SAMPLING PERFORMANCE

A high-volume air sampler was developed to collect organic compounds in the gas and particulate phases at flows up to 1.4 m3/min. Quartz fiber or Teflon membrane filters can be employed; use of a backup filter allows correction for the direct adsorption of gaseous analytes to the filter. Most of the filtered air passes through two 1.27 cm thick polyurethane foam sheets (PUFSa) in series; the remainder passes through two Tenax cartridges in series. The thin, filter-size (20 cm x 25 cm) PUFSs permit high-flow rates with minimal pressure drop. An adequate sample volume can be obtained in a minimum amount of time, minimizing the probability that atmospheric concentration fluctuations will cause volatilization losses from, or adsorption gains to particles on the filter. With sample volumes of 500-700 M3, at approximately 16-degrees-C, breakthrough from the first PUFS was < 30% for compounds less volatile than octadecane (C18) and phenanthrene. Good agreement was obtained for the compounds determined on both the PUFSs and the Tenax beds.