Improving Water Condensation Bioaerosol Sampling Using a Concentrated Sample Inlet Flow
DREW JONES, Mark Hernandez, Marina Nieto-Caballero, Sonia Kreidenweis, Shantanu Jathar, Colorado State University
Abstract Number: 493
Working Group: Bioaerosols
Abstract
Bioaerosols can be collected with high efficiency using water condensation capture samplers, (e.g., BioSpot-VIVAS and BioSpot-GEM, Aerosol Devices), while avoiding certain challenges presented with filter-based collection such as sample desiccation and incomplete recovery of sampled bioaerosol during subsequent sample elution. Despite their high collection efficiency, these samplers have low collection flow rates (≤15 LPM) compared to other types of samplers, possibly limiting their utility when sampling in environments with low ambient concentrations of bioaerosols (e.g., outdoor settings). Concentrating the sampled airstream using a virtual impactor in the instrument’s inlet may solve the challenge of low sampler flow rates.
In this study, a multi-jet virtual impactor was designed and fabricated based on design parameters from published work by F. J. Romay et al. The cut-point and concentration factor of the virtual impactor were characterized using a range of monodisperse aerosols in a chamber study. The virtual impactor was then integrated into the inlet flow path of a water condensation capture sampler (BioSpot-VIVAS). Additionally, a chamber study with model bioaerosols is planned to compare the collection ability of the virtual impactor augmented sampler with an unmodified sampler. We hypothesize that the virtual impactor in line with the sampler will allow for effective flow rates ranging from ten to twenty times greater than those from the commercially available sampler, translating to ten to twenty times more bioaerosol collection in the same sampling time. This work will help improve bioaerosol collection for aerobiome studies (e.g., metagenomics, and metatranscriptomics), particularly those performed in low bioaerosol concentration environments.