Multiphase Reactivity of Benzotriazole Ultraviolet Stabilizers
YAO YAN HUANG, Jonathan Abbatt,
University of Toronto Abstract Number: 65
Working Group: Aerosol Chemistry
AbstractBenzotriazole ultraviolet stabilizers (BUVs) are a class of chemicals used to prevent the degradation of materials from ultraviolet (UV) radiation that are added to various consumer and industrial products such as paints, polymers and food packaging, and textiles. They are highly recalcitrant with a growing concern as an environmental contaminant, observed in water bodies, sediment, and in airborne dust and aerosols. Their reactivity and degradation pathways in the environment are still largely unknown. Their presence in airborne dust, aerosols, and consumer products suggests a potential exposure and transformation potential in everyday environments that many other additives are also privy to. In a series of laboratory experiments, the multiphase reactivity of two BUVs (UV-328, UV-P) with gas phase oxidants (·OH, O
3, and ·NO
3) and UV-C radiation was investigated. All experiments were carried out in an oxidation flow reactor for up to 24h at different mixing ratios. The reaction was monitored off-line by liquid chromatography tandem mass spectrometry (LC-MS/MS). BUVs were deposited at 2.5 nm and 0.5 nm thick layers and dissolved in less-reactive thin films of dioctyl sebacate. Both pure UV-328 and UV-P were found to be recalcitrant to heterogenous O
3 oxidation up to 1000 ppb in 24h. Additional experimental results in other reaction conditions will be reported, as well as an analysis of reactivity within a common consumer product such as plastic. The reaction products, if any, will be investigated and identified using liquid chromatography high resolution mass spectrometry (LC-HRMS) and a reaction pathway will be proposed. This work aims to provide information about the environmental fate of BUVs and their reactivity in complex environments.
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