W4: Initial Turf Compound Testing

Purpose

• This week, our team began to confirm the quantitative analysis of our polypropylene (PP) fibered turf samples using the Pyrolysis-GC/MS machine. We worked with Dr. Yuxuan Zhang to put the ground-up fibers into metal containers for the Single-Shot Pyrolysis testing. Below are multiple graphs that quantifies our results by retention time and chemical name. Sample 1 and 2 are both from the same ground up PP fiber sample, just in different quantities. This testing was to also solidify our knowledge of using the pyro GC/MS machine and will be used later in the semester for collected filtrated samples from our boxes. 

• Laser diffraction cannot be used for size analysis on samples, so a sieving method is going to have to be used for size analysis. Smallest sieve size is 57 μm, while microplastics are scoped to 1 μm, so we will have some limitation there. Sieving will be used once a proper shredding method has been identified and a shredded PP fiber sample is ready to be tested. 

Sample 1 Data

Sample 1 is a sample of 220 μg of ground up PP fiber. Visible in graph 1 is the compound peaks and their retention times. Based off Table 2 above, for PP fibers we can see that 2,4-dimethylhept-1-ene is a large component in PP, which is confirmed in graph 1, where the largest peak is 2,4-dimethyl-1-heptene. This confirms that the sample is indeed PP. Report 1 gives a summary of all the present compounds in the samples, which may be important later on when separating contaminants from the microplastics.

Sample 2 Data

Sample 1 is a sample of 480 μg of ground up PP fiber. Graph 2 is the compound peaks and their retention times. The difference between the first and second sample results is that there was more sample present in the testing, which could lead to more pollutants present in the sample, but also a larger peak for compounds, with more being present or more concentrated. This sample just again confirms that PP was present in the sample.