Broadband Photoacoustic Spectroscopy Using Quantum Cascade Laser Arrays For Compositional Analysis Of Airborne Aerosols

Building on our previous development of a compact, portable, and low SWaP gas analyzer (11 '' x 6.7 '' x 5.1 '', 7.8 Ibs) based on photoacoustic spectroscopy and using broadband quantum cascade laser arrays, we demonstrate here compositional analysis of airborne aerosols using this instrument. With an integration time of 330-ms per laser, and similar to 70 seconds for a spectrum covering 950-1500 cm(-1), our instrument showed a detection sensitivity at the mg/m(3) level for solid and liquid-loaded solid aerosols. Additionally, Malathion-loaded aerosols can be discriminated from pure Syloid aerosols based on their absorption features. The preliminary results show a potential path for developments of a portable real-time aerosol composition analyzer.