Comparative study on decay ratios of laser-induced fluorescence between asbestos and building materials

Abstract

Decay ratios of the laser-induced fluorescence emitted from five types of asbestos (chrysotile, crocidolite, amosite, tremolite, and anthophyllite) and six types of building materials (glass wool, rock wool, rock fiber, talc, plaster, and cement) in the broad wavelength region from 350 to 650 nm were investigated by using an ultraviolet laser pulse of 266 nm. The dependences of the decay ratios on the wavelength were compared, and evaluated in an attempt to numerically discriminate asbestos from other building materials. It was observed that the decay ratios of each material were not constant over the wavelength region, but varied in the wavelength over time. There were significant differences in the decay ratio between asbestos and fibrous building materials in the wavelength region from 360 to 400 nm. The wavelength region of 405-407 nm was found to be optimum in order to identify types of asbestos and to discriminate asbestos from the building materials by comparing the decay ratio at a delay time of 10 ns after the incidence of a laser pulse. © 2014 The Japan Society for Analytical Chemistry.