Validation of the Aerosol Beam-Focused Laser-Induced Plasma Spectrometer (ABF-LIPS) for Metal Emission Characterization

摘要

The Aerosol Beam-Focused Laser-Induced Plasma Spectrometer (ABF- LIPS) is a pulsed laser beam focused onto an aerosol sample to ignite a plasma, degrading compounds to their elements, vaporizing them to an unstable, excited state. As atoms return to ground state, light released at element-specific wavelengths can be observed using time-resolved spectroscopy. The ABF-LIPS was tested at the Naval Aviation Depot (NADEP), San Diego, CA and at Tooele Army Depot (TEAD), UT. The NADEP test produced useable data for only one emissions source, but these data did not correlate with spiking levels of the three test metals (Cd, Cr, Ni). The ABF-LIPS was modified prior to TEAD field tests. These data correlated well with spiking levels, but agreement with reference method results was not within the USEPA PS-10 RA acceptance criteria of 20% for any of the five test metals; thus primary performance criteria were not met. Further development of ABF-LIPS is required prior to more validation testing and eventual regulatory acceptance. Laboratory testing of the system components yielded better accuracies, suggesting that adaptation of system components to a portable, field-deployable unit used in these tests resulted in compromised data accuracy, and/or that the inherent nature of field testing with a higher degree of uncontrolled variables were likely reasons for the failed field testing.