Method development for the HPLC-MS/MS determination of tire chemicals in airborne particulate matter. Application to...

Airborne pollution from vehicle tires has garnered increasing scientific concern due to its widespread presence and potential health hazards in densely populated urban areas. The heterogeneous chemical makeup of tire treads and tire wear particles (TWPs), as well as the analytical challenges in distinguishing them within complex environmental matrices, underscores the urgent need for robust detection techniques. Given the well-documented health effects of particulate matter (PM) exposure and the lack of clarity regarding the specific contribution of tire-related particles to overall air pollution risk, advancing analytical capabilities in this domain is essential. In this study, a High-Performance Liquid Chromatography coupled with Tandem Mass Spectrometry (HPLC-MS/MS) method was developed for the targeted determination of 20 TWP-associated compounds in urban atmospheric aerosols. The selected analytes include benzotriazoles, benzothiazoles, antioxidants, diphenylguanidine and its derivatives, and triazine compounds - all commonly used constituents in tire formulations. The analytical procedure is based on Accelerated Solvent Extraction utilizing acetonitrile as the extraction solvent, followed by quantification through HPLC-MS/MS. This approach aims to improve understanding of the contribution of TWPs to ambient PM in urban environments. Method validation results indicated recovery rates ranging from 18 % to 128 % across all analytes. Furthermore, the method demonstrated high sensitivity and precision, with limits of quantification ranging from 1.0 ×10^-5 to 3.0 × 10^-2 µg m^-3, and relative standard deviations below 20 % for most compounds. The developed method was successfully validated and applied to the analysis of PM₁₀ aerosols (particulate matter <10 µm) collected from Strasbourg, France, over 14 weeks, and of the 20 targeted tire-related chemical markers, 15 were quantified in the air samples, with concentrations ranging from 0.005 to 25.5 µg m^-3, and a median of 0.11 µg m^-3. The most frequently detected compounds included 1,3 diphenylguanidine (DPG), phenylguanidine carbonate salt (PGC), andtolytriazole-5 (TTA), which were present in over 85% of samples.