Searching Nanoplastics: From Sampling to Sample Processing

Abstract

Nanoplastics (NPs) are considered emerging pollutants, namely unregulated contaminants whose toxic effect on humans and the environment has been demonstrated or suspected. They are the result of the physical fragmentation of the plastics that over time reach smaller dimensions (<100 nm). The issues related to the characterization and quantification of NPs in the environmental matrices are mainly related to the infinitesimal size, to the fact that they are found in bulk, and to the different physico-chemical forms in which the same polymer can evolve over time by degradation. To deal with the study of a new class of pollutants it is necessary to assess the entire analytical method, carefully considering every single step (sampling, cleanup, qualitative, and quantitative analysis) starting from the validation method in the laboratory. This paper reviews the analytical method steps, focusing on the first ones, which the current literature often underestimates: laboratory tests, sampling, and sample processing; in fact, most errors and the quality of the analyses often depend on them. In addition, all newly introduced sample processing methods were examined.

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

“…In this perspective, digestion is a key step which should be suitable to remove the organic matter, preserving, however, the properties and quantity of NPs [ 33 , 55 ]. Two different approaches are commonly adopted: chemical degradation and enzymatic digestion [ 16 , 35 ]. The first approach involves the use of different chemicals for acid (e.g., HCl and HNO 3 ) or alkaline (e.g., NaOH and KOH) digestion, whilst the second utilizes specific enzymes (e.g., proteinase K, papain) that degrade the organic matrix.…”

“…Chemical degradation enables efficient removal of the background matrix and is a cost-effective approach. However, acid treatment has recently been questioned because it tends to destroy and cause aggregation of NPs polymers [ 16 , 49 ]. Therefore, an alkaline approach, which is less invasive, is recommended [ 51 ].…”

“…Scientific interest in the potential toxic effects of NPs on living organisms has significantly grown in recent years [ 16 ], suggesting that these contaminants are potentially more harmful than MPs [ 11 , 17 , 18 , 19 , 20 ]. However, our understanding of NPs remains at early stages [ 21 ], and there is a paucity of data regarding both the environmental exposure and toxic effects of NPs on biota at realistic environmental concentrations [ 22 , 23 ].…”

Understanding microplastic pollution in the Nordic marine environment – knowledge gaps and suggested approaches

“…The analytical techniques for detection of nanoparticles of plastic have only recently started to become available after years of ongoing development [10,29,28]. The low micron and submicron particle sizes are relevant for immunotoxicological studies because these are the most bioavailable and may interact with the immune system cells of the fish.…”

In Situ Fluorescent Illumination of Microplastics in Water Utilizing a Combination of Dye/Surfactant and Quenching Techniques

“…Endeavors to observe/detect MPs in the environmental matrix are probably a first step to handle such a threat. The detection procedure of MP generally consists of separation (e.g., filtration), size categorization (e.g., sieving), purification (i.e., removal of organic residues), identification, and quantification [ 16 , 17 , 18 , 19 , 20 , 21 ]. For example, filtration is a common step to separate MPs from aqueous samples such as surface water, groundwater, marine water, and wastewater [ 17 , 18 , 22 , 23 , 24 ].…”