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K2 Test For Screening Asbestos.
Asbestos Identification and Measurement. Proceedings of a Topical Symposium Sponsored by the American Conference of Governmental Industrial Hygienists 1979:18-20
A colorimetric test for asbestos (1332214) screening was described. The test was used to detect magnesium ions (22537220) (Mg) and divalent iron (15438310) (Fe) from asbestos in bulk samples. The test was based on the formation of colored complexes with Mg and Fe released from asbestos. In testing for Mg, a sample about the size of a pea was mixed with glycerin in a plastic beaker. Water was added. The sample was filtered and washed. The filter was then transferred to a teflon dish and ground. A drop of phosphoric-acid was added, followed by a drop of sodium-hydroxide. Ten drops, in 5 drop portions, of p-nitrobenzeneazo-alpha-naphthol in 2 normal sodium-hydroxide were added. A blue color showed the presence of Mg, indicating the possible presence of chrysotile (12001295). No color change indicated the absence of chrysotile. In the Fe test, a small portion of sample was placed on a teflon dish to which a drop of hydrofluoric-acid was added. Five drops of 1,10-phenanthroline were added. A red color indicated the possible presence of amosite (12172735) or crocidolite (12001284). When used to test 70 field samples, 52 were correctly identified by the method. Only 18 samples gave false positive results. The test was 100 percent accurate in identifying 22 samples that did not contain asbestos. These results were verified by transmission electron microscopy. The author notes that the test is useful for identifying asbestos in sprayed on samples and ceiling tiles.
Hygiene; Calorimeters; Analytical-instruments; Calorimetry; Particle-counters; Dust-exposure; Analytical-models; Asbestos-dusts; Asbestos-fibers; Air-monitoring;
1332-21-4; 22537-22-0; 15438-31-0; 12001-29-5; 12172-73-5; 12001-28-4;
Asbestos Identification and Measurement. Proceedings of a Topical Symposium Sponsored by the American Conference of Governmental Industrial Hygienists
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division