Sensitive Detection and Identification of Isovanillin Aerosol Particles at the pg/cm3 Mass Concentration Level using Raman Spectroscopy
Journal Article - Open Access
MIT Lincoln Laboratory Lexington United States
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A compact Raman spectroscopy system with high sensitivity to chemical aerosols has been developed. This system has been used to detect isovanillin aerosols with mass concentration of 12 pgcm3 in a 15 s signal integration period with a signaltonoise ratio of32. We believe this represents the lowest chemical aerosol concentration and signal integration period product ever reported for a Raman spectroscopy system. The Raman system includes i a 10 W, 532nm cw laser, ii an aerosol flow cell, iii a 60x aerosol concentrator, iv an f1.8 Raman spectrometer with a spectral range of 4001400 cm1 and a resolution of 4 cm1, and v a lownoise CCD camera 1340x400 pixels. The collection efficiency of the Raman system has been determined to be 2.8. Except for the laser cooling subsystem, the Raman system fits in a 0.61 m x 0.61 m x 0.61 m box.
- Atomic and Molecular Physics and Spectroscopy
- Miscellaneous Detection and Detectors
- Chemical, Biological and Radiological Warfare