Protein Corona-Mediated Extraction for Quantitative Analysis of Nanoplastics in Environmental Waters by Pyrolysis Gas Chromatography/Mass Spectrometry

Abstract

There is a growing concern about the effects of nanoplastics on biological safety and human health because of their global ubiquity in the environment. Methodologies for quantitative analysis of nanoplastics are important for the critical evaluation of their possible risks. Herein, a sensitive yet simple and environmentally friendly extraction approach mediated by protein corona is developed and coupled to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) for nanoplastic determination in environmental waters. The developed methodology involved the formation of protein corona by addition of bovine serum albumin (BSA) to samples and protein precipitation via salting out. Then, the resulting extract was directly introduced to Py-GC/MS for nanoplastic mass quantification. Taking 50 nm polystyrene (PS) particles as a model, the highest extraction efficiency for nanoplastics was achieved under the extraction conditions of BSA concentration of 20 mg/L, equilibration time of 5 min, pH 3.0, 10% (w/v) NaCl, incubation temperature of 80 °C, and incubation period of 15 min. The extraction was confirmed to be mediated by the protein corona by transmission electron microscopy (TEM) analysis of the extracted nanoplastics. In total, 1.92 and 2.82 μg/L PS nanoplastics were detected in river water and the influent of wastewater treatment plant (WWTP), respectively. Furthermore, the feasibility of the present methodology was demonstrated by applying to extract PS and poly­(methyl methacrylate) (PMMA) nanoplastics from real waters with recoveries of 72.1–98.9% at 14.2–50.4 μg/L spiked levels. Consequently, our method has provided new insights and possibilities for the investigation of nanoplastic pollution and its risk assessment in the environment.

Nanoplastics: Status and Knowledge Gaps in the Finalization of Environmental Risk Assessments

“…Based on evidence compiled to date, it can be emphasized that the measured nanoPS concentrations in river waters could produce sublethal effects in Caenorhabditis elegans . In fact, the concentrations (1.92–2.82 μg·L −1 ) measured by Zhou et al [ 37 ] are higher than the proposed sublethal effective threshold of 1 μg·L −1 , which has been proven to alter the locomotor ability and induce ROS production. The ubiquitous presence of NPs, their uptake by organisms, and their potential to act as vectors for toxicants and pathogens render their risk assessments a priority on stakeholders’ agendas at the global level.…”

“…To the best of our knowledge, only eight studies have successfully extracted these contaminants from abiotic field samples. These studies have documented the occurrence of nanoscale plastic particles in seawater [ 36 ], rivers [ 37 ], snow [ 38 , 39 ], air [ 40 ], soil [ 41 ], sand [ 42 ], and tap water [ 43 ]. As shown in Table 2 , only a few studies have simultaneously reported the concentration and relative polymeric types of NPs present in samples [ 37 , 38 , 43 ].…”

Evaluating the Occurrence of Polystyrene Nanoparticles in Environmental Waters by Agglomeration with Alkylated Ferroferric Oxide Followed by Micropore Membrane Filtration Collection and Py-GC/MS Analysis

“…Meanwhile, plastic waste has become a big problem, and it is estimated that global plastic waste could rise to 408 million tonnes in 2050. , Plastic wastes entering the environment may degrade into microplastics (MPs, 1 μm–5 mm) and nanoplastics (NPs, <1 μm) − by mechanical weathering, UV radiation, and biological degradation. , The adverse effects and potential risks of MPs and NPs have been extensively studied. − MPs were reported to induce intestinal damage to zebrafish and nematode, and the toxicity of MPs and NPs is closely related to their size and shape. , Another study also reported that MPs and NPs have distinct toxic mechanisms on microalgae growth . Moreover, NPs can be accumulated in plants and organisms. ,, It is hypothesized that because of their larger surface to volume ratio NPs may adsorb more external toxic compounds than MPs, leading to greater risk. − Although previous studies have reported the detection of NPs in the environmental samples including waters, high-altitude snow, polar ice, organisms, and soils ,,− and several studies gave accurate concentrations of NPs in environmental samples by highly sensitive detection methods, ,,, the pollution status of NP contamination is still unknown to a large extent.…”

“…However, the complicated sample preparation process and high cost are unappealing, and further NP identification is also needed. , Spectroscopic techniques, such as Fourier transform infrared spectroscopy and Raman spectroscopy, are commonly used to identify plastic particles. However, the two methods usually fail to characterize nanoscale particles, as their size detection limits are about micromolar levels. , Common mass spectrometry includes single particle-inductively coupled plasma mass spectrometry (sp-ICP/MS), , thermal desorption–proton transfer reaction–mass spectrometry (TD-PTR-MS), ,, and pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). ,,,,,, By labeling NPs with Au nanoparticles, sp-ICP/MS can accurately count the particle number concentrations of NPs; however, the mass concentration of NPs is missing. , By low-pressure evaporation/sublimation and TD-PTR-MS, NPs were detected in environmental samples with simple matrices, such as polar ice and high-altitude snow. ,, Py-GC/MS is an effective method to quantify NPs. However, due to the relatively high detection limit, proper enrichment methods are required to analyze NPs in environmental samples.…”

Distribution, bioaccumulation, and trophic transfer of palladium-doped nanoplastics in a constructed freshwater ecosystem

“…However, most of the present studies have focused on the uptake and biological toxicity of MPs and NPs; 16–18 quantitative information about their transport and fates in ambient media including water, sediment, and biota, which play a vital role in environmental risk assessment, is barely available due to analytical challenges, especially for NPs with smaller sizes. 19 To date, electron microscopy, 20,21 Fourier transform infrared (FTIR) and Raman spectroscopy, 21–26 and mass spectrometry-based techniques 27–29 have been adopted for qualitative and/or quantitative quantification of NPs. Unfortunately, these techniques are tedious, error-prone, less sensitive, and inapplicable to complex samples.…”