Simultaneous light scattering and intrinsic fluorescence measurement for the classification of airborne particles

We describe a prototype laboratory light-scattering instrument that integra tes two approaches to airborne particle characterization: spatial light-sca ttering analysis and intrinsic fluorescence measurement, with the aim of pr oviding an effective means of classifying biological particles within an am bient aerosol. The system uses a single continuous-wave 266-nm ultraviolet laser to generate both the spatial elastic scatter data (from which an asse ssment of particle size and shape is made) and the particle intrinsic fluor escence data from particles in the approximate size range of 1-10-mu m diam eter carried in a sample airflow through the laser beam. Preliminary result s suggest that this multiparameter measurement approach can provide an effe ctive means of classifying different particle types and can reduce occurren ces of false-positive detection of biological aerosols. (C) 2000 Optical So ciety of America.