Design and development of an electrostatic sampler for biological aerosols with high concentrating rate.
Proceedings of the AAAR 26th Annual Conference, September 24-28, 2007, Reno, Nevada. Mt. Laurel, NJ: American Association for Aerosol Research, 2007 Sep; :229
Integration of bioaerosol sampling with modern analysis techniques, such as PCR, requires samplers that can not only efficiently collect particles, but also to concentrate them in small amounts of fluids. In this research, we began development of a novel bioaerosol sampler, where a combination of electrostatic collection mechanism with superhydrophobic (\Lotus leaf\ type) collection surface allows for efficient particle collection, removal and concentration in small water droplets: 10 to 50 micro-L. This new sampling concept allows achieving very high sample concentration rates (up to 1 million) and could be applied to detect low concentrations of bioaerosols in various environments. The prototype Electrostatic Precipitator with Superhydrophobic Surface had a shape of a closed halfpipe, where top surface served as a ground electrode, while 3 mm wide collecting electrode covered by a superhydrophobic substance was positioned in a groove of the flat bottom surface. Airborne particles drawn into the sampler were positively charged and then by the action of electrostatic field deposited onto the negatively charged electrode. The sampler was positioned at a approximately 20 degree angle, and the injected water droplets rolled-off of electrode's surface removing deposited particles. Our tests have shown that at a sampling flow rate of 10 L/min we achieved retention efficiency of about 90% for 3 micrometer PSL particles. By using 20 and 40 micro-L water droplets, we achieved concentration rates as high as 100,000 as indicated by counting of removed particles by microscopy. Majority of the particles are removed by the first applied droplet, and few particles are removed by subsequent droplets. Tests with other particles also yielded high concentration rates, which points to the suitability of this new method for measuring low concentrations of bioaerosols. The sampler's performance is being improved further by adjusting the sampling flowrates, strength of ion source and collection voltage.
Biological-factors; Aerosols; Sampling; Samplers; Analytical-processes; Particulate-sampling-methods; Particulates; Fluids; Electrostatic-fields; Electrostatic-precipitators; Electrostatic-precipitation
Proceedings of the AAAR 26th Annual Conference, September 24-28, 2007, Reno, Nevada
Rutgers the State of New Jersey - New Brunswick