Investigation of the Determination of Respirable Quartz on Filter Media Using Fourier Transform Infrared Spectrophotometry.
NIOSH 1989 Sep:71 pages
The use of Fourier transform infrared spectrophotometry to determine quartz (14808607) in respirable dust directly on filter media was investigated. The study involved 15 different 25 millimeter filters which might be used in a respirable dust sampler. The limit of detection in practical operating conditions was estimated to be 3 micrograms with linearity in excess of 1 milligram. A limiting factor to the sensitivity was the spatial inhomogeneity of the filter background. Steps were developed to correct for the filter background and the absorbance of relatively nonstructured interferences. Two methods to correct for the interference of the overlapping absorbance banks of other minerals with those of quartz were devised. Scaled spectral subtraction of reference spectra of the interferences provided results that did not differ significantly from those which were obtained by a more traditional approach. Both methods overcorrected for the presence of the interference. The particle size within the respirable range influenced the absorbance signal per unit weight of quartz. Potential problems due to carbon- dioxide or water vapor were easily controlled. Reproducible spectra were obtained by purging the sample compartment for 20 minutes.
NIOSH-Author; Analytical-methods; Chemical-analysis; Analytical-chemistry; Dust-exposure; Air-sampling; Mineral-dusts; Quartz-dust;
NTIS Accession No.
Methods Research Branch, Division of Physical Sciences and Engineering, NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio, 71 pages, 23 references