Quantitative analysis of nanoplastics in environmental and potable waters by pyrolysis-gas chromatography–mass spectrometry

Nanoplastics are emerging environmental contaminants, but their presence in environmental and potable water remains largely understudied due to the absence of quantitative analytical methods. In this study, we developed and validated a pretreatment method that combines hydrogen peroxide digestion and Amicon® Stirred Cell ultrafiltration (at 100 kDa, approximately 10 nm) with subsequent detection by pyrolysis gas chromatography–mass spectrometry (Pyr-GC/MS). This method allows for the simultaneous identification and quantification of nine selected nanoplastic types, including poly(ethylene terephthalate) (PET), polyethylene (PE), polycarbonate (PC), polypropylene (PP), poly(methyl methacrylate) (PMMA), polystyrene (PS), polyvinylchloride (PVC), nylon 6, and nylon 66, in environmental and potable water samples based on polymer-specific mass concentration. Limits of quantification ranged from 0.01 to 0.44 µg/L, demonstrating the method’s ability to quantitatively detect nanoplastics in environmental and potable water samples. Most of the selected nanoplastics were detected at concentrations of between 0.04 and 1.17 µg/L, except for PC, which was consistently below the limit of detection (<0.44 µg/L). The prevalent polymer components in the samples were PE (0.10 – 1.17 µg/L), PET (0.06 – 0.91 µg/L), PP (0.04 – 0.79 µg/L), and PS (0.06 – 0.53 µg/L) nanoplastics. The presented analytical method offers an accurate means to identify, quantify, and monitor nanoplastics in complex environmental and potable water samples. It fills gaps in our understanding of nanoplastic pollution levels, providing a valuable methodology and crucial reference data for future studies. The environmental fate and potential human exposure risks associated with nanoplastics have garnered significant attention, but the occurrence and concentrations of nanoplastics in environmental and potable water samples remain largely understudied due to analytical complexities. In this study, we developed an analytical workflow capable of pre-concentrating, identifying, and quantifying levels of nanoplastics present in complex environmental and potable waters. Among the nine targeted nanoplastics (PE, PP, PET, PS, PMMA, PC, Nylon 6, PVC, and Nylon 66), eight were successfully identified and quantified, with PE, PET, PP, and PS being the most prevalent. This research provided valuable insights into the actual pollution levels of these targeted nanoplastics in environmental and potable water samples, offering crucial reference data for future studies, and demonstrating the effectiveness of the proposed analytical method.