Since the TenneSwim ended on September 29th, the “swimming professor” Andreas Fath and his graduate student Juri Jander have been busy analyzing their numerous water quality samples. The TenneSwim team is particularly interested in how much plastic is transported by the river.
The challenge in answering this question lies in the fact that rivers break down large plastic items (such as empty water bottles) into smaller particles, so-called microplastics. “PerkinElmer’s transportable IR Spectrometer Spectrum Two makes it very easy for us to identify what type of plastic we are dealing with, no matter the size of the object or particle”, explains Fath. To demonstrate how this process works, the research team collected plastic waste from the Tennessee River and determined what material it is made of.
The picture above shows the identification of Polyethylene terephthalate (PET). The black line represents the profile of a particular type of plastic; this information is saved in the spectrometer’s database (the “library”). In contrast, the green line shows the profile of the material the object or particle of interest is made of. You can see that the two lines are almost identical. Therefore, it is evident that the team is dealing with PET. “This spectrometer enables us to understand what types of plastic the Tennessee River carries”, says Fath.
This spectrometer will also be used to determine the presence and concentration of microplastics in water quality samples. The only difference to the analysis of larger macroplastics is that the researchers need a microscope to detect the much tinier microplastics particles, which then need to be separated from other substances in the samples such as algae, sediment, and organic debris. This work will take the research team several weeks. Stay tuned!