Detection and Quantification of Nanoplastics and Microplastics in Australian Drinking Water

Nanoplastics (10–1000 nm) are an emerging contaminant of concern in drinking water, yet quantitative data remain scarce compared to microplastics (>1000 nm). Here, we present a comprehensive assessment of both nanoplastic and microplastic contamination in Australian drinking water. An integrated analytical workflow combining pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) screening for mass concentrations, combined with asymmetrical flow field-flow fractionation with multiangle light scattering (AF4-MALS) and off-line Py-GC-MS/MS, nanoparticle tracking analysis (size), and electron microscopy (morphology) was applied to quantify and characterize polymer particles across size scales. Average mass concentrations ranged from 0.5 to 1.5 μg/L for selected microplastics and 0.3 to 0.7 μg/L for nanoplastics. Tap water samples contained significantly higher concentrations than bottled water. Detected polymers included polypropylene, Nylon-66, Nylon-6, polystyrene, and polyethylene terephthalate, with lower concentrations of poly(methyl methacrylate) and polyethylene also detected. Nanoparticle counts in tap water were estimated at 10⁶–10⁷ particles/mL. The indicative identification of polypropylene nanoplastics demonstrates the effectiveness of the AF4-MALS–Py-GC-MS workflow for high-throughput characterization. These findings indicate the presence of polypropylene nanoplastics in drinking water and highlight the need to consider them in future assessments of water quality and potential human exposure.