Today is the last day of the second week of my internship at the Climate and Sustainability REU. Compared to last week, I had more of a hands-on experience in the lab this week. I worked with PFOA for the first time. I am not sure what I was expecting it to look like, especially since I was mainly reading about how harmful it can be, but it was just a white powdery substance. I would have never guessed it could have been such a toxic substance. At this point, I measured the desired mass of PFOA and then contaminated our two zeolite samples. After weighing substances like zeolites, copper, and PFOA, I found that the weighing portion of experiments was very time-consuming. This thought brought me back to how my mentor said the bulk of experiments is usually the weighing portion.

Aside from lab work, since my PI’s lab is in the process of moving into the new O’Connor building, I had the chance to look at the academic journals in my PI’s old office. There were various journals to look over, but out of the few I looked at, I found a few journals I wanted to take home. I also thought of my dad when looking at these journals since he loves to learn.  Journals like these are difficult to get access to, so I made sure to get at least one my dad would like. Furthermore, I surprisingly found a journal that had an article on a similar research project I did at my community college. It was over how certain chemical filters in sunscreens impact the environment, specifically coral reefs, and how their exposure can potentially impact human health. Despite them being in my possession, I have yet to read any of the journals but I am looking forward to reading about a wide arrangement of topics and learning new things.

Toward the end of the week, we continued to do more lab work, and my chemistry skills were put to work. It was mainly conversions of units to adjust to the units the automatic pipettes. I also learned the math behind a calibration curve, which is still something I am trying to wrap my head around, however, I am slowly coming to a general understanding of calibration curves and their purpose in the High-Performance Liquid Chromatography (HPLC). Additionally, I learned how to use syringes so we can filter our zeolites from the solution substances. We attached the syringes to small disposable filters, and it was quite difficult to work with them. The part I struggled with the most was pulling up part of the syringe that allowed for the liquid to enter. Additionally, having to continuously move the syringe down as the liquid went down was also challenging because the solution could overflow.

We finished the experiment, and although we were hoping there would be an observable difference in the absorbance in both the calcinated ion-exchanged zeolite and the non-calcinated ion-exchanged zeolite, no difference was observed using the HPLC. We did not view this as a setback, but rather a learning experience. It wasn’t that the experiment failed but rather the calcination did not work. Because the previous absorbance of the contaminated zeolites did not have a difference at the calcinated temperature, we went back to the baseline. Previous research established that beta zeolite can adsorb some of PFAS without any treatment while gamma zeolite cannot unless it is treated. In this case, the treatment is calcination and/or ion exchange. To make sure our samples confirm this idea, we have created six samples of PFAS-contaminated gamma zeolite samples and one PFAS-contaminated beta zeolite sample. The beta zeolite sample did not go through a transition-metal ion exchange, two of the gamma zeolite samples were only ion-exchanged, two gamma zeolites were calcinated at differing temperatures, and the last one was pure gamma zeolite. These samples were shaken overnight and went through the HPLC to observe the concentrations of PFAS and confirm what we already know.

After running our six samples through the HPLC, we determined a plan to follow in the following week. I am still striving to improve my abilities in analyzing data and deciphering what that means to adjust future steps. Overall, I feel like I have gotten a good grasp of what qualities make a responsible and diligent scientific researcher.