This research investigates the physical collection characteristics of a novel and compact (combined dimensions similar to 2.5 l) air-to-liquid aerosol collector recently developed by the Lawrence Livermore National Laboratory. In this collector, the air flow is drawn into an annular, centripetal slot, which directs the aerosol flow into a small volume of liquid at the sampler's center, thereby imbedding airborne particles in the liquid. A mist eliminator positioned above the liquid prevents liquid droplets from escaping the sampler thus improving its performance. We found that the sampler's collection efficiency increases with decreasing width of the annular slot, and with increasing flow rate, mist eliminator speed and sample volume. When operating at a flow rate of 275 l/min and collecting particles into 1 ml of liquid, the sampler can achieve concentration rates as high as 275,000/min. We also determined that by changing the sampler's operational parameters we can move its collection efficiency curve over a wide range of particle sizes, thus adjusting the sampler's cutoff size from 0.45 mu m to 2.1 mu m. The sampler's small size and its high collection performance make it suitable for many biodetection strategies. (C) 2005 Elsevier Ltd. All rights reserved.