Spectrometry. What is it?

This week I worked with the Raman spectrograph again and was able to start analyzing the polymer composition of some of the plastics in my samples. The spectrograph is a scientific instrument that fires a laser at a particle and measures the light scatter that occurs when the laser strikes the object. The Raman spectrograph is yet another new method that I have learned to further my research, and while there is a learning curve, I think I feel comfortable using the machine and now understand the fastest way to get through my samples without sacrificing research integrity. The picture here is the captured spectrum of one single particle from one of my samples. There is a lot of noise in the spectra, which is quite normal; any dust or surface particulates, as well as the glass microscope slide that the plastic is on can cause background noise. The final step in the analysis process, therefore, is to remove the noise from the spectrum so that the data can be compared to spectral libraries that contain control samples for various materials (in my case, plastics).

Although I didn't take a picture of the spectrum, I did have at least one spectrum that didn't appear to be of a plastic. There were not visible peaks and valleys within the known plastic polymer range, suggesting that the material was not a plastic. The Raman process is the final step in identifying plastics, since visual analysis--especially at the micron size--cannot account for differences between cotton fibers and plastic fibers. 

The next few weeks will be quite busy. Although I won't be doing a lot more Raman work over the next few weeks due to my other research plans, I will hopefully get back to analyzing the plastics soon. The best part of my research is that there are 4 different processes that I do to work through the samples, which means that if I feel like I am in a rut, or if the work gets too monotonous, I can change which step I am working on and reinvigorate myself. Also, something to look forward to: I am hoping to present some information about what I have learned from analyzing the Fall and Winter sediment samples. I want to talk to some individuals about how appropriate it is to present data prior to writing a paper and prior to having all the data, so I can't make any promises; just know that I'm really hoping to share some cool things in the future with all of you.

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