Abstract
In the Anthropocene, the pollution of the environment and the burden of living organisms caused by plastic particles and plastic-associated chemicals are omnipresent [1, 2]. The smallest plastic particles and a plethora of organic and inorganic plastic additives can be detected in almost all ecosystems and tissues of various organisms [3,4]. Nevertheless, validation of the corresponding chemical-analytical processes is still challenging.
Trace metals, heavy metals and metalloids play an important role as process catalysts or additives in plastic production as well as in achieving certain product properties. Under environmental conditions and dependent on the weathering stage of the plastic material, such metal(loid)s can be leached out from plastic particles, but they can also be enriched on the surface from the surrounding environment. This contribution will underpin how elemental analysis can act as a powerful and versatile tool for the characterization of plastics and plastic particles. We developed a fully validated protocol to quantify metal(loid)s in plastics and plastic particles of different polymer types in a metrologically traceable manner. The protocol was applied to validate micro- and nanoplastic (MNP) sampling protocols by using metal-doped, realistic reference MNPs. Metal-doped MNPs enabled the quantitative tracking of MNPs in complex systems. To understand metal(loid) sorption, kinetic profiles showing the sorption of metal(loid) cations to small microplastics (MPs) and the subsequent release of sorbed ions were studied. To also understand metal(loid) leaching, eight plastic consumer products were leached in distilled water under strong ultraviolet (UV) light simulating eight months of Central European climate and compared to their respective dark controls metal(loid) analysis. The leaching study revealed substantial release of toxic metal(loid)s, which was further enhanced under UV exposure. In the future, studies and research projects dealing with the release of MNPs and chemical additives should include the use of ICP-MS/MS or another elemental analysis techniques to obtain a complete picture of the chemical footprint of MNPs in the environment.
References
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[3] Springer Nature, 2023. Plastic waste is everywhere — and countries must be held accountable for reducing it. Nature 619 (7969), https://doi.org/10.1038/d41586-023-02252-x.
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