Characterization of microplastics in water bottled in different packaging by Raman spectroscopy

Abstract

Raman spectroscopy was applied to quantitatively and qualitatively characterize microplastics (MPs) in bottled water packaged in three different materials: polyethylene terephthalate (PET), recycled PET (rPET) and glass. The results showed a low mean concentration of MPs in all samples, with higher values in glass bottles (8.65 ± 5.39 p L⁻¹) than in PET (5.09 ± 3.28 p L⁻¹) or rPET (3.33 ± 1.34 p L⁻¹) bottles. Through the use of a method capable of detecting smaller particles, MPs of 20–100 μm were dominant and fragments were the most abundant particle shape. PET was the prevalent polymer in PET bottles underlying the possible contribution of packaging in MP contamination, while polyethylene (PE) with additives prevailed in rPET and glass bottles, suggesting a contribution from the cap. A standardized protocol would allow comparable data to be obtained and allow an objective assessment of exposure, in view of plans to monitor contaminants of emerging concern (including MPs) under recent European legislation.