Advances in Ultra-Trace Analytical Capability for Micro/Nanoplastics and Water-Soluble Polymers in the Environment: Fresh Falling Urban Snow

Discarded micro/nano-plastic inputs into the environment are emerging global concerns. Yet the quantification of micro/nanoplastics in complex environmental matrices is still a major challenge, notably for soluble ones. We herein develop in-laboratory built nanostructures (zinc oxide, titanium oxide and cobalt) coupled to mass spectrometry techniques, for picogram quantification of micro/nanoplastics in water and snow matrices, without sample pre-treatment. In parallel, an ultra-trace quantification method for micro/nanoplastics based on nanostructured laser desorption/ionization time-of-flight mass spectrometry (NALDI-TOF-MS) is developed. The detection limit is similar to 5 pg for ambient snow. Soluble polyethylene glycol and insoluble polyethylene fragments were observed and quantified in fresh falling snow in Montreal, Canada. Complementary physicochemical studies of the snow matrices and reference plastics using laser-based particle sizers, inductively coupled plasma tandem mass spectrometry, and high-resolution scanning/transmission electron microscopy, produced consistent results with NALDI, and further provided information on morphology and composition of the micro/nano-plastic particles. This work is promising as it demonstrates that a wide range of recyclable nanostructures, inlaboratory built or commercial, can provide ultra-trace capability for quantification for both soluble polymers and insoluble plastics in air, water and soil. It may thereby produce key missing information to determine the fate of micro/nanoplastics in the environment, and their impacts on human health. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study developed a method for quantifying micro/nanoplastics in water and snow matrices without sample pre-treatment, using mass spectrometry techniques and nanostructures. Soluble polymers and insoluble plastics were successfully observed and quantified in fresh falling snow. Through comprehensive physicochemical studies, information on morphology and composition of micro/nano-plastic particles was provided.