Improved Aerosol Collection by Combined Impaction and Centrifugal Motion

Abstract

ABSTRACT A new principle for collecting airborne particles, including microorganisms, has been introduced by injecting the particles into a swirling airflow from where they are removed onto a collection surface. A dry surface, a surface coated with an adhesive substance or a surface wetted by a liquid swirled onto the collection surface from a reservoir below can be used in the new collection method. The swirling air motion and aerosol injection into it are achieved by drawing the airborne particles through nozzles that are directed at an angle toward the collection surface. This principle has been incorporated into a new sampler that has been named “Swirling Aerosol Collector” (SAC; commercially available as the “BioSampler” from SKC Inc., Eighty Four, PA). The physical performance of the SAC has been evaluated against the widely used AGI-30 impinger by measuring the particle concentrations upstream and downstream of each sampler with an aerodynamic particle sizer. Tests with monodisperse polystyrene lat...