Rapid single-particle chemical imaging of nanoplastics by SRS microscopy
Qian N, Gao X, Lang X, Deng H, Bratu TM, Chen Q, Stapleton P, Yan B, Min W (2024). Proceedings of the National Academy of Sciences.
What they found
Using a new stimulated Raman scattering imaging method that can identify single plastic particles under 100 nm, the team estimated about 2.4 ± 1.3 × 10^5 plastic particles per litre of bottled water, about 90% of them nanoplastics. That is orders of magnitude more than earlier counts that could only see microplastics. Polyamide was a common major contributor across the three brands.
Read this too
Materić (PNAS 2024, doi 10.1073/pnas.2411099121) argued the blanks were inappropriate because the paper's own SI says the lab's ultrapure water had similar plastic contamination to the bottled water. The authors replied (doi 10.1073/pnas.2415874121) that contaminated lab water would have been the wrong blank and that brand profiles differed.
- Sample
- 3 brands of bottled water bought at one large US retailer
- What it can't tell you
- Only three brands, bought at the same time from one retailer. The lab had no plastic-free water, so blanks were clean dry filters rather than processed lab water; a published letter argues this makes the numbers unreliable. Count assumes particles are evenly spread on the filter. A methods paper, not a survey of bottled water.
- Funding
- Europe PMC lists NIEHS (NIH) grants; authors declare no competing interest.
- Topics
- Drinking water, Methods
- Checked against
- Abstract (PMID 38190543); three brands, one retailer and blank method from Results (open-access full text PMC10801917); COI from full text; critique from Materić letter full text (PMC11621622)