Research on a Rapid and Simple Detection Method for Asbestos

摘要

An improved method was developed for identifying asbestos fibers, especially when present with non-asbestiform fibers. The test involves the use of two organic fluorescent dyes and a fluorescent microscope for detecting chrysotile asbestos, the most prevalent form currently in use. This form has a surface binding affinity for morin hydrate and 4,5-dihydroxy-naphthalene-2,7-disulfonic acid (DHNDS), two organic dyes. Tagging of the asbestos fibers occurs at or near chrysotile's isoelectric point of 4.4. Its high binding strength resists displacement by pH changes or organic solvents of diverse polarities. The binding specificity is narrow; no other material examined possesses an affinity for either dye. These findings enhance detectability of chrysotile fibers by optical microscopy since such fibers are more readily discerned among non-asbestiform fibers or extraneous debris on the observed film. This method can be used as a screening technique for quick and accurate detection of asbestos-containing materials in public buildings.