From rivers to the tap: Investigation of micro and nanoplastics in drinking water by pyrolysis-GC-MS

The occurrence of micro-and nanoplastics (MNPs) in freshwater has been globally recognized. This raised the question of possible human exposure to MNPs through drinking water from freshwater sources. Recent studies have shown that potable water may contain MNPs, but a high degree of variation in concentrations has been reported. These variations are attributed to the differences between raw water and the treatment and distribution processes. However, the analytical techniques employed for the identification and quantification of MNPs also have a significant role at the level of reported. To be able to estimate the MNP associated risks via drinking water consumption, reliable exposure concentrations with lower size limits of polymers are urgently needed. In the present study, a sensitive method was developed to detect and quantify MNPs in water samples based on the protein corona mediated aggregation of particles followed by filtration and analysis with pyrolysis-gas chromatograph-mass spectrometry (Py-GC-MS). The method was validated using different types of water and acceptable recoveries were obtained for PE, PP, PVC and PS ranging from 97 to 118%. Given the ubiquity of microplastics in freshwater systems and increased particle numbers with decreasing polymer sizes, this method is a promising tool to quantify MNPs in water samples and to evaluate the risks for human health.