Microplastics are a ubiquitous presence in the world, found from Arctic snow to Antarctic ice and everywhere in between. There are trillions of microplastic particles floating on surface water, and everyone from infants to adults are presumed to be ingesting anywhere from dozens to tens of thousands of these particles every day. But the science of microplastics, especially the incredibly tiny, potentially-cell-disrupting nanoplastics, is only just beginning. The effects of these microplastics isn't well known, largely because the scale of microplastics isn't well known. They are, by definition, difficult to see.
Unless you're looking in a second dimension.
Existing techniques for identifying single microplastic particles do exist and are well-established, such as Fourier-Transform Infrared (FTIR) and Raman spectroscopy, but they also have well-established limitations for polymer-chemical mixtures, small particle sizes, and sample analysis time. When trying to wrestle with a problem of this magnitude, slow and limited techniques can struggle to keep up with the demand.
A full-scan chromatography technique, such as Gas Chromatography Time-of-Flight Mass Spectrometry (GC-TOFMS) would allow for a full view of every compound in a given sample. When extended into the second dimension (GC×GC TOFMS) and combined with Pyrolysis (Py) and Thermal Desorption (TD), this technique allows for powerful chromatographic separation with high quality deconvoluted mass spectral data with minimal sample preparation. Microplastic degradation products, additives, and other complex mixtures of chemicals found in the environment can all be resolved, detected, and identified in the same sample analysis.
To prove this was more than just a theory, LECO Europe teamed up with Imperial College, London, and Helmholtz Zentrum, Munich, to perform a proof of concept study on this approach to analyzing samples for microplastic particles. Learn more with their article in Chromatography Today.