Quantitative Analysis of Asbestos-Containing Materials Using Various Test Methods

The advantages of X-ray powder diffraction (XRPD) analysis are its non-destructive nature, reliability, fast and easy sample preparation, and low costs. XRPD analysis has been used for mineral identification and the quantitative/qualitative determination of various types of fibrous minerals in asbestos-containing materials (ACMs). In order to test the detection limit of ACMs by XRPDD, standard samples with various concentrations of ACMs (0.1%, 1%, and 3%) were fabricated using three matrix materials (talc, vermiculite, and sepiolite). Asbestiform tremolite and chrysotile were identified in the XRPD profiles of the samples with 1% and 3% ACMs. Their integral intensities were positively correlated with the concentrations. However, the XRPD peak of asbestos was not found in the samples with 0.1% ACMs. Therefore, scanning and transmission electron microscopy were utilized to investigate the samples with a very low concentration of ACMs. Although the ACM concentration (0.1%) was negligible and its direct observation was time-consuming, electron microscopy allowed for the detection of asbestos in several matrix materials. Thus, a combination of XRPD and electron microscopy improve analytical performance and data reliability.