Enhancing detection of asbestiform minerals in asbestos contaminated talc using FTIR and multivariate data analysis

Talc has been widely used for decades in cosmetic and personal care products because of its unique properties. However, certain talc deposits have historically been found to contain asbestiform minerals, making the detection of these contaminants critical for mitigating asbestos exposure risks in consumer products. To investigate this, laboratory generated mixtures of talc/anthophyllite asbestos and talc/tremolite asbestos were prepared at various concentrations. These mixtures underwent thorough processing with sodium polytungstate (SPT), a heavy liquid, followed by centrifugation, settling, and extraction of separated mineral components. Each extracted sample was analyzed using Fourier Transform Infrared (FTIR) spectroscopy and mineral type was predicted through multivariate data analysis (Partial Least Squares-Discriminant Analysis (PLS-DA)). The PLS-DA model, trained on specific wavenumber regions displaying distinct mineral features, successfully identified anthophyllite and tremolite asbestos in most separated samples. However, in cases where misclassification occurred-where asbestiform minerals were labeled as talc or unassigned-a secondary separation procedure was required. The integration of heavy liquid separation, FTIR spectroscopy, and PLS-DA offers a promising approach for enhancing the detection of asbestiform minerals in asbestos-contaminated talc.