AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Measurement of Crystalline Silica Aerosol Using Quantum Cascade Laser-based Infrared Spectroscopy
SHIJUN WEI, Pramod Kulkarni, Kevin Ashley, Lina Zheng, Centers for Disease Control and Prevention, NIOSH
Abstract Number: 754 Working Group: Instrumentation and Methods
Abstract An approach using quantum cascade laser (QCL)-based infrared (IR) spectroscopy to quantify airborne concentrations of crystalline silica aerosol has been developed. Three aerosol collection methods were investigated for effective coupling with QCL: i) conventional total aerosol filter collection; ii) focused spot sample collection directly from the aerosol phase; and iii) dried spot RCS analysis after deposition using liquid sample slurries. Spectral analysis methods were developed to obtain IR spectra from the collected particulate samples in the range 750-1030 cm-1. The system was calibrated and the QCL results compared with standardized methods using Fourier transform infrared (FTIR) spectrometry. Results show that significantly lower detection limits for crystalline silica (~330 ng) could be achieved with effective microconcentration and careful coupling of the particulate sample with the QCL beam. These results offer promise for further development of sensitive filter-based laboratory methods and direct-reading portable monitors for near real-time measurement of crystalline silica aerosol.