ConclusionThe goal of this experiment/project was to determine if lakes and rivers in our area contain non-degraded steroidal estrogens. The first sample fiber was contaminated so the results were inconclusive and erroneous. The second sample, however; revealed many different analytes in the water tested. Two of these, Cholest-8-en-one and benzamide are major components in pharmaceuticals. The other m/z peaks associated with E1 and E2 that were observed were very small, indicating that there are only trace amounts of estrogen in Lake Massabesic.If I were to repeat this experiment I would make sure that the fibers used were desorbed and clean. Our school lab is not equipped to desorb polyacrylate fibers at high temperatures above 250°C. I would research more the uses and properties of the fibers. The other process I would change would be the timing. I did the filtration, microextraction and derivatization 48 hours before the GC-MS analysis. This also could have caused a chemical change on the fiber before analysis..The Green Chemistry Principles addressed in this experiment were:1. Safer Solvents and Auxiliaries
The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.
Headspace derivatization is a greener way to prepare a sample for GC-MS analysis. Other methods employ multiple solvents to achieve derivatization.2. Design for Energy Efficiency
Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.
The derivatization step could be done in a 800MHz microwave for 8 minutes, but the PA fiber would have to be detached from the case.3. Prevention
It is better to prevent waste than to treat or clean up waste after it has been created
Polyacrylate fibers can be used many times, in some cases up to 100. They are being used more frequently for SPME because of their reusability and cost effectiveness.
This project revealed to me the many facets of scientific research. I spoke with scientists from as far away as Australia and Germany, and as close as Concord, NH and Chelmsford MA. I realized that the reason published research papers have multiple authors and pages of references is because science is one big collaboration. Each researcher builds on a body of scientific knowledge that is astoundingly huge. Everyone I worked with was extremely helpful and gave freely their ideas, knowledge, time, and materials. This one project helped me to determine where I am heading in my education, on to graduate school. Why? Because science is so much fun!