Assessing CeO2 and TiO2 Nanoparticle Concentrations in the Seine River and Its Tributaries Near Paris

Motivation for detecting engineered nanoparticles (ENPs) in the environment comes from a need to understand fate and behavior of these materials natural matrices. The difficulty lies low expected ENP particle number concentration (PNC) presence large variable background NPs. We report PNCs characteristics cerium-bearing (Ce-NPs) titanium-bearing (Ti-NPs) an aquatic matrix (the Seine River three its tributaries) with use single ICP-MS (spICPMS) electron microscopy (FEG-SEM). Ce-bearing Ti-bearing particles were observed suspended particulate matter collected onto 0.2 μm 1 kDa filters, using FEG-SEM imaging. At Marnay-sur-Seine, upstream point, Ce-NPs Ti-NPs 0.47 ± 0.07 × 10 6 1.35 0.17 as measured by spICPMS. maximum PNC both Ti-NPs, 1.59 0.10 mL −1 5.89 , respectively, found Marne River, major tributary Seine. It was shown that downstream each confluence, increase is observed, suggesting significant contribution different tributaries. Mass balance flows elemental ratios Ce/La showed Oise CeO 2 NPs exists. anthropogenic TiO ENPs further assessed Ti/Al, Ti/V, Ti/Y ratios. Near constant element below Orge Paris city suggest neither contribute significantly Ce or Ti NP concentrations. study provides investigation strengths limitations application spICPMS samples contributes data currently highly-limited dataset on backgrounds rivers, information key assessing potential quantifying input surface waters. Of total mass Ti, 83 90%, could be detected