A review on recent advances in the environmental occurrence of benzothiazoles: analytical methods and their role as non-exhaust traffic tracers

The study of benzothiazoles (BTHs) in the atmosphere is gaining attention due to their strong link with non-exhaust traffic emissions, particularly those resulting from tire wear. While these compounds have been widely investigated in water and soil, their presence in aerosol remains less explored, with reported atmospheric concentrations ranging from approximately 50 pg m −3 in remote areas up to 2000 pg m −3 in urban environments. Given their consistent detection in urban environments, BTHs could serve as effective markers for tracking non-exhaust traffic emissions, thereby enhancing our understanding of their contribution to air pollution and facilitating source identification. This review focuses on recent advances in the study of BTHs, providing an updated overview of their environmental occurrence and potential as traffic-related tracers. Additionally, it highlights the latest developments in analytical methods for their detection, emphasizing progress made in the past few years via UHPLC-MS/MS techniques, which achieve limits of detection down to sub-ng L −1 levels in aqueous matrices. This review concludes that to reliably employ BTHs as tracers, it is essential to analyse a broader range of derivatives and transformation products; such a comprehensive analytical approach is crucial for distinguishing between diverse emission sources and accurately accounting for the compounds’ environmental fate.