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Author
Tuchman, D. P.
Title
Research Toward Direct Analysis of Quartz Dust on Filters Using FTIR Spectroscopy.
Coporate
Bureau of Mines, Pittsburgh, PA
Report
IC 9309
1992
21 p.
Keywords
dust | quartz | filters | FT-IR | spectroscopy
Abstract
The U. S. Bureau of Mines is investigating Fourier transform infrared (FTIR) spectroscopy for on-filter quartz analysis of respirable dust. A custom accesory is described for full-face examination of filters utilizing a large-diameter infrared (IR) beam. The accessory positions samples to match diameters with that of the diverging analytical beam. Sample absorbance is then measured. With nonuniform deposition of dust on collection filters being a major issue for such analyses, this approach is the most direct way to accomplish sample area averaging. The approach is unconventional since it utilizes large-beam geometries instead of the usually desired minimized beam dimensions. The isues and problems involved in the analysis of quartz on a filter matrix are discussed. Absorption bands chosen, light-scattering effects, curved baselines, random noise, interference fringes, and possible solutions to technical difficulties are the topics covered. The more significant findings include a 20-mug detection limit for quartz when the custom accesory is used and minimal occurrence of light-scattering effects at low wavenumbers. The custom accessory performance was satisfactory and merits further work. With continued research, an on-filter method for quartz analysis of respirable dusts seems achievable.