Tuesday, April 25, 2017

URSP Student Daniel Cairnie Studies the Binding of Pharma-chemicals to Aquatic Humic Substances (AHS)

My name is Dan Cairnie and I am a senior chemistry major pursuing research in the field of environmental chemistry. Right around the time of Spring 2016, I really started to enjoy my experience in the lab because of all the instruments I learned how to use in my classes. The instrument I enjoyed the most (and still do) was the fluorescence spectrophotometer, also known as a fluorimeter. For some inexplicable reason, I love looking at the spectrophotometer output the peaks and troughs that come with a great sample reading. With the current research I am doing, I have the pleasure of seeing those peaks and troughs every day I enter the lab. I am fortunate enough work alongside Dr. Greg Foster in a project that studies the quenching effect of a commonly used pharmaceutical, carbamazepine (CBZ), on humic and fulvic acids (HA and FA) found in water bodies. By studying these interactions, we can gain a better understanding of the binding characteristics between the CBZ and HA/FA components.

I usually come into Dr. Foster’s laboratory on the weekends to experiment, since it is quiet and I am a bit more relaxed. However, most of the time I spend in the lab is dedicated to preparing solutions to run with the fluorimeter. It brings up recent memories of working in the chemistry department’s stock room, where preparing various solutions precisely was a staple in my routine there. While this process is certainly tedious and time-consuming, the joy I get when I finally see an accurate spectrum that supports literature makes everything worth it. So far, I have discovered that in dilute concentrations of CBZ and HA/FA, a much simpler quenching model, known as the Stern-Volmer equation, can be used in place of an extensive multivariate analysis. This multivariate analysis, known as the Ryan-Weber model, requires the mathematical programming software, MATLAB, in order to attain more quantitative insights on how HA/FA binds with CBZ. Using the Ryan-Weber model in experimentation is my ultimate goal once the Stern-Volmer method of analysis is perfected. Humic and fulvic acids are an integral part of the environmental remediation process, and with our research, we aim to understand how this can be affected by pharma-chemicals and what can be done long-term to mitigate any negative consequences.