Comparison between Two FT-IR Spectroscopy Analytical Procedures for Micrograms Determination of Asbestos Species in Bulk Materials

Abstract

The Fourier Transform Infrared (FT-IR) spectroscopy is by far known to be a useful technique for qualitative and quantitative analysis of asbestos in bulk samples, since all asbestos species exhibit intense absorption peaks in the 4000 -400 cm -1 region of the infrared spectrum. In the present work, we compare the accuracy and precision of two analytical procedures (the Linear Calibration Curve Method and the Method of Addition) for the quantitative determination of asbestos in a host matrix. We have found that, providing careful samples preparation, both techniques quantify the asbestos content at the level of few micrograms with good precision. Due to less expensive equipment requirements and shorter analysis time, FT-IR can be a competitive analytical technique in the characterization of asbestos containing material with the respect to diffractometry or electron microscopy.

Diffuse Reflectance Infrared Fourier Transform Spectroscopy for the Determination of Asbestos Species in Bulk Building Materials

“…Chrysotile shows double O–H peaks stronger at about 3685 cm −1 and weaker at 3655 cm −1 [ 26 ]. A broad O–H bending band is present at 605 cm −1 , Si–O stretching vibration at 1069, 1033 and 959 cm −1 , and evident bands at about 606, 434 and 300 cm −1 can be assigned to Mg–OH bending frequency [ 20 , 25 ].…”

“…Quantitative analyses using calibration curves are based upon measuring a property of a sample that changes with the analyte concentration [ 20 ]: in the present case, the calibration curves are obtained by plotting the height of the absorption peak, h M , as a function of the concentration, C x ; i.e. , h M = A + B C x .…”

“…For these reasons, although samples require careful pre-treatment before analysis, FTIR could be an alternative approach with respect to other used techniques [ 16 – 19 ]. In our recent paper, we have compared different analytical FTIR procedures for a low content of asbestos in bulky materials [ 20 ], also focusing our attention on sample preparation: classic FTIR measurements are done on powders dispersed in potassium bromide (KBr), which is transparent to infrared radiation. The way powders are obtained by massive ACM is simple milling (both by hands or automatic), but it is not a trivial process: the powder size should be less than one micron on average, and the milling step should not damage the fiber structure; otherwise, the result is false [ 21 ].…”

Determination of the concentration of asbestos minerals in highly contaminated mine tailings: An example from abandoned mine waste of Cretaz and Emarese (Valle d'Aosta, Italy)

“…This discrepancy may be possibly due to: (1) interference of antigorite and chlorite present in the investigated samples with a severe overlap of their absorption bands to that of chrysotile, and (2) deviation of the linearity of the curve intensity of the chrysotile absorption band vs. concentration for large chrysotile contents. The breaking of the linearity assumption has been already observed by De Stefano et al (2012). They observed that in the case of chrysotile, the peak intensity is a quadratic-like function of the concentration in the extended concentration range.…”

Micro X-Ray Fluorescence Imaging Coupled With Chemometrics to Detect and Classify Asbestos Fibers in Demolition Waste

“…In this work, benchtop micro-XRF was utilized to identify and classify asbestos fibers (Bonifazi et al, 2015;Bonifazi et al, 2018). The proposed strategy, based on the combined use of micro-XRF imaging and chemometric techniques, can be a valid and efficient analytical approach supporting the currently adopted asbestos recognition techniques, such as Fourier transform infrared spectroscopy (FT-IR) (De Stefano et al, 2012), Raman spectroscopy (Petriglieri et al, 2015), polarized light microscopy (PLM) (Lee et al, 2008) and scanning electron microscopy (SEM) (Gandolfi et al, 2016). All these techniques require the preparation of samples and usually allow punctual measurements and/ or small areas mapping.…”