Investigating Analytical Techniques for Microplastic Characterization and Quantification

Exposure to microplastics and nanoplastics throughout daily life is inevitable, yet still poses a variety of unknowns and concerns in biological and environmental systems. Microplastics are defined by the National Oceanic and Atmospheric Association (NOAA) as all plastic particles <5mm in size; either produced to be that size (primary) or via degradation of larger particles (secondary). Ubiquitous in nature, microplastics have successfully infiltrated marine systems, foodstuffs, soil/sediments, and biological systems. The identification and characterization of these persistent species is crucial in understanding their toxicological effects and impacts. Accordingly, their analysis has branched into many analytical means. Spectroscopic techniques, such as Raman and micro- Fourier Transform Infrared spectroscopy (µ-FTIR), along with Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC-MS) have gained traction recently. Advancements in techniques like these have yielded increased instrument sensitivity and accuracy while providing straightforward analysis of the structural and compositional characteristics of plastics within a variety of biological and environmental analyses. Exploring the impact of these physiochemical characteristics further allows for insight as to the persistence of certain plastic types in different systems. Beyond identification and characterization, quantification is another important tool in determining the prevalence of a certain microplastic type within systems. This data, collectively, creates a representative profile of plastic species and provides the foundations necessary for development of environmental policies and mitigation practices.