A two-stage cyclone using microcentrifuge tubes for personal bioaerosol sampling

Area of Science:

• Environmental Science
• Aerosol Science
• Biotechnology

Background:

• Personal aerosol samplers are crucial for monitoring human exposure to airborne contaminants.
• Growing interest in analyzing bioaerosols using molecular and immunological methods necessitates improved sampling techniques.
• Existing methods may not efficiently collect or preserve bioaerosols for downstream molecular analysis.

Purpose of the Study:

• To develop and evaluate a novel personal bioaerosol sampler.
• To enable direct molecular and immunological analysis of collected bioaerosols.
• To fractionate airborne particles by aerodynamic diameter during personal sampling.

Main Methods:

• A two-stage cyclone personal sampler was designed to collect bioaerosols into 1.5 ml microcentrifuge tubes.
• The sampler's performance was assessed using fluorescent microspheres and aerosolized fungal spores.
• Cut-off diameters, aspiration efficiency, and collection efficiency were determined at different flow rates (2 and 3.5 L min⁻¹).

Main Results:

• The sampler achieved first and second stage cut-off diameters of 2.6 µm and 1.6 µm at 2 L min⁻¹, and 1.8 µm and 1 µm at 3.5 L min⁻¹.
• Aspiration efficiency was ≥98% for particles ≤3.1 µm and high for larger particles (89-96% for 6.2 µm).
• Over 92% of aerosolized fungal spores were collected in the tubes, with minimal loss to the back-up filter.

Conclusions:

• The developed personal sampler effectively collects bioaerosols suitable for molecular analysis (e.g., polymerase chain reaction, immunoassays).
• The two-stage cyclone design allows for aerodynamic size fractionation.
• This sampler is a valuable tool for personal bioaerosol monitoring and can be adapted for larger-scale air quality studies.