Laser-induced breakdown spectroscopy analysis of asbestos L. Caneve a, * , F. Colao a , F. Fabbri a , R. Fantoni a , V. Spizzichino a , J. Striber b a ENEA, FIS-LAS, C.R. Frascati (RM), Italy b INOE2000, 1 Atomistilor St., 76900 Bucharest, Romania Received 24 November 2004; accepted 12 May 2005 Available online 12 September 2005 Abstract Laser-induced breakdown spectroscopy was applied to test the possibility of detecting and identifying asbestos in different samples in view of the perspective at field operation without sample preparation which is peculiar to this technique. Several like-resin materials were first investigated by laser-induced breakdown spectroscopy, in order to find an asbestos container assuring safe laboratory operation during the material characterization aimed to identify indicators suitable for a quick identification on field. Successively, spectra of asbestos samples of both in serpentine and amphibole forms were measured and the variability in elemental composition was calculated from the emission spectra. Ratios of intensities of characteristic elements were tested as indicators for asbestos recognition. Laser-induced breakdown spectroscopy results were compared with those obtained by analyzing the same asbestos samples with a scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, a good correlation was found for Mg/Si and Fe/Si, thus showing the capability of laser-induced breakdown spectroscopy as a diagnostic tool for this category of materials. In particular, it was demonstrated that the method based on two indicators derived from laser-induced breakdown spectroscopy intensity ratios allows to discriminate between asbestos and cements in single shot measurements suitable to field operation. D 2005 Elsevier B.V. All rights reserved. Keywords: LIBS; Asbestos; Intensity ratios 1. Introduction Asbestos term is used for a group of hydrated mineral silicates with microcrystalline structure and fibrous aspect. This kind of minerals is generally divided in two groups depending on the chemical and crystallographic properties: the serpentines and the amphiboles. Crocidolite and amosite are the most common fibrous forms of the amphibole group, while the chrysotile, in the serpentine group, is the most abundant asbestos mineral and it has been the most commonly used in the building industry. The asbestos content into the materials is almost all constituted of chrysotile, crocidolite and amosite [1]. Some peculiar characteristics, like flexibility, incombust- ibility and chemical-resistance, make the asbestos a very useful material for many industrial applications. In the recent past, it was usually used for fireproofing, electrical insulation, building materials, brake linings, and chemical filters. On the other hand, the asbestos is also widely known for its strong interaction with the human body and its detrimental health effects [2,3]. Materials with asbestos inside do not represent a danger if they are not deteriorated, but whatever action causing their fracture could give rise to serious problems due to fibers fragmentation. The asbestos identification in soil and buildings is then very important, due to its former wide spread use, but it is a critical issue due to the similarity of asbestos with other harmless minerals that can be easily confused with it. Moreover, the low concentration and small dimension of asbestos fibers can make their characterization very difficult [4]. The techniques of analysis more usually employed for asbestos fibers investigation are the scanning electron 0584-8547/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.sab.2005.05.014 B This paper was presented at the 3rd International Conference on Laser Induced Plasma Spectroscopy and Applications (LIBS 2004), held in Torremolinos (Ma ´laga, Spain), 28 September – 1 October 2004, and is published in the special issue of Spectrochimica Acta Part B, dedicated to that conference. * Corresponding author. Spectrochimica Acta Part B 60 (2005) 1115 – 1120 www.elsevier.com/locate/sab