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Publicação
Environmental markers of plastics and microplastics
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Orientador(es)
Resumo(s)
The slow reaction rates to chemical and photo chemical degradation are well-known properties of plastics. However, large plastic surfaces exposed to environmental conditions release particles and compounds that affect ecosystems and human health. The aim of this work was to identify compounds associated with the degradation of polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC) micro plastics (markers) on silica and sand and evaluate their use to screen microplastics on natural sand. Products were identified by using targeted and untargeted LC-HRMS analysis. All polymers underwent chemical oxidation on silica. PE released dicarboxylic acids (HO2C-(CH2)n-CO2H (n = 4−30), while PS released cis/ trans-chalcone, trans-dypnone, 3-phenylpropiophenone, and dibenzoylmethane. PVC released dicarboxylic acids and aromatic compounds. Upon irradiation, PE was stable while PS released the same compounds as under chemical oxidation but at lower yields. Under the above condition, PVC generated HO2C-[CH2−CHCl]n-CH2−CO2H and HO2C-[CH2−CHCl]n-CO2H (n = 2−19) dicarboxylic acids. The same products were detected on sand but at a lower concentration than on silica due to better retention within the pores. Detection of markers of PE and PS on natural sand allowed us to screen microplastics by following a targeted analysis. Markers of PVC were not detected before or after thermal/photo-oxidation due to the low release of compounds and limitations associated with surface exposure/penetration of radiation.
Descrição
Palavras-chave
Polyethylene Polystyrene Polyvinyl chloride Thermal oxidation Photo-oxidation Product distributions Sand surface
Contexto Educativo
Citação
Editora
American Chemical Society
Licença CC
Sem licença CC