Determination of microgram quantities asbestos by x-ray diffraction: chrysotile in thin dust layers of matrix material.
Lange BA; Haartz JC
Anal Chem 1979 Apr; 51(4):520-525
An X-ray diffraction (XRD) method was developed to measure microgram quantities of chrysotile asbestos (1200195) in pure or matrix material samples. Chrysotile and talc samples were ground and deposited on silver membrane filters. The filters were ashed prior to analysis. Ultrasonic treatment reduced particle size and increased sensitivity. Comparable results were obtained when the raw net densities were normalized by an external or substrate standard. X-ray absorption corrections were necessary to reduce measurement errors. Detection limits were 2 micrograms of fiber per square centimeter for both pure and matrix samples. The authors conclude that this XRD method is specific for chrysotile, has a low detection limit, and offers excellent precision. It can accurately measure small amounts of chrysotile in the presence of large amounts of matrix material, when determinations by the counting method are generally difficult. This technique could be automated, and may be applied to other asbestiform materials. The authors recommend sample pretreatment and X-ray line profile analysis to reduce interference from other minerals.
NIOSH-Author; Measurement-instrumentation; Analytical-methods; Detectors; Asbestos-fibers; Airborne-dusts; X-ray-diffraction-analysis; Respiratory-system-disorders
B. A. Lange, U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, Ohio 45226