Record Display for the EPA National Library Catalog

RECORD NUMBER: 1418 OF 1422

OLS Field Name OLS Field Data
Main Title X-Ray Analysis of Airborne Asbestos. Interim Report: Sample Preparation.
Author Fatemi, M. ; Johnson, E. T. ; Whitlock, R. R. ; Birks, L. S. ; Gilfrich., J. V. ;
CORP Author Naval Research Lab., Washington, D.C.;Environmental Sciences Research Lab., Research Triangle Park, N.C. Emissions Measurement and Characterization Div.
Year Published 1977
Report Number EPA/600/2-77/062;
Stock Number PB-266 671
Additional Subjects Asbestos ; X ray diffraction ; Aerosols ; X ray analysis ; Alignment ; Air pollution ; Air filters ; Feasibility ; Fibers ; Concentration(Composition) ; Design criteria ; Chemical analysis ; Gas analysis ; Air pollution detection
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB-266 671 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 38p
Abstract
A measurement technique, suitable for submicrogram quantities of asbestos, using a combination of fiber alignment and x-ray diffraction was previously introduced. The x-ray measurement of aligned fibers is a straightforward operation. However, it has since been found that the sample preparation itself depends on several parameters which need critical control. The composition of the alignment medium is established as 10-20 ppm (W/V) of parlodion (cellulose nitrate) in distilled amyl acetate. The effect of filter pore-size has been shown to be more significant than previously thought. Fiber losses in the range of 50-80% of total mass are not unlikely, depending on the fiber size distribution. Similarly, ultrasonification has been shown to affect fiber size distribution and subsequent fiber retention by filters. Ambient relative humidity suitable for alignment of single drops has been established to be in the range of 35% to 45% at 22C to 20C, respectively. Parameters involved in radio frequency ashing of filters are also discussed. It is shown that ashing quality and subsequent dispersion depends on the filter membrane, and improves as this concentration is increased.