AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
A Multiparameter Bioaerosol Spectrometer (MBS)
Paul Kaye, Warren Stanley, Edwin Hirst, MARTIN GALLAGHER, Niall Robinson, Ian Crawford, University of Hertfordshire
Abstract Number: 105 Working Group: Bioaerosols: Characterization and Environmental Impact
Abstract The real-time in situ detection of airborne biological particles is required in wide range of fields from military and counter-terrorism agent detection through to atmospheric cloud microphysical research and air quality monitoring. To help meet this requirement, the authors had previously developed the WIBS (Wideband Integrated Bioaerosol Sensor) instrument that has been increasingly used in atmospheric and environmental research studies and is now available commercially from Droplet Measurement Technologies Inc. (Boulder, CO, USA). Here, we report on a new instrument, the Multiparameter Bioaerosol Spectrometer (MBS), that has been developed from the WIBS technology to help maximise the potential of combining particle fluorescence spectroscopy with high-resolution light scattering analysis in the detection and classification of airborne biological particles.
Whereas the WIBS instrument records intrinsic particle fluorescence over just two wavebands, 310-400nm and 420-650nm (corresponding to the peak emissions from bio-fluorophores tryptophan and NADH), MBS records the fluorescence over eight channels from approximately 310 to 640nm. This improves discrimination of biological particles from ‘interferent’ non-biological particles that may exhibit similar fluorescence properties. Similarly, while WIBS uses a simple quadrant detector to assess light scattering asymmetry and hence particle shape, the MBS uses two 512-pixel CMOS detector arrays to record high-resolution sections through the particle’s spatial light scattering pattern, potentially yielding data on both the macroscopic shape and surface characteristics of the particle. Again, this can enhance the prospects of particle classification and reduce false-positive bio-particle detection.
The MBS records the size, 8-channel fluorescence spectrum, and high-resolution particle scattering data from up to 100 particles/s, with additional particles counted only. Development of clustering algorithms to process these multiparameter data are continuing, but examples of raw MSB data from a variety of biological and non-biological particles will be given together with initial examples of how this data may be processed to yield particle classification.