Vibrational spectroscopic studies of asbestos and comparison of suitability for remote analysis

Raman, mid-infrared (MIR) and near-infrared (NIR) spectroscopic methods have been applied to the analysis of fibrous (asbestos) and non-fibrous forms of serpentine and amphibole minerals. This paper describes the first application of NIR diffuse reflectance spectroscopy to the study of asbestos minerals. In addition, a more generally applicable Raman spectroscopic study, in terms of multiple excitation wavelengths and asbestos materials, than has previously been made is reported. Improvements in spectral quality (especially in the OH stretching region) over previously published MIR spectroscopic data are also reported. The results of this work indicate the NIR diffuse reflectance spectroscopy appears to be the preferred method for the remote analysis of asbestos due to the relatively simple spectra in the wavenumber range 7400-6900 cm(-1), the high signal-to-noise ratio and spectral contrast of the spectra, the capability of using silica fiber-optics cables, and the time required to perform the analysis relative to the other vibrational spectroscopic techniques.