2010 JISAO Summer Research Internship
Measuring aluminum concentration near underwater volcanoes in the Pacific
As a rising chemistry/physics major at Reed College in Portland, Oregon, I applied to the JISAO internship program to get an introduction to scientific research and to learn about opportunities for graduate study. I have always had an interest in environmental science and JISAO's program looked like an excellent opportunity to challenge myself in this area. I am honored to have been chosen as one of JISAO's seven interns this summer.
During my project I worked with trace element chemist Dr. Joseph Resing at the Pacific Marine Environmental Laboratory (PMEL) at NOAA's Sand Point facility. My research focused on quantifying the concentration of aluminum (Al) from seawater samples obtained near submarine volcanoes and thermal vents in the Pacific Ocean. Unlike elements such as iron and manganese, Al is only released in appreciable quantities by actively erupting volcanoes, so studying the Al concentrations near submarine volcanoes allowed me to learn about the intensity and duration of recent eruptions.
I had little idea what I was getting into at the beginning of the summer but this internship turned out to be great for me because it combined several of my interests including computer programming, automation, engineering, and chemical analysis. During the first week of my internship I wrote computer code in BASIC to program an autosampling device to pump precise volumes of fluid through a series of tubes to a fluorometer. The output of the fluorometer allowed me to determine the Al concentration of injected water samples.
This fluorometric method for determining Al concentration is called flow injection analysis. Al does not easily fluoresce (emit light after electromagnetic excitation), so the first step was to combine the injected seawater with a reagent called lumogallion. The Al is in the seawater reacts with lumogallion to form a coordination compound that does fluoresce. Next, the seawater sample is reacted with brij-35, a 35-carbon detergent that intensifies the fluorescence of the sample through a process called micellar enhancement. Finally, the sample is injected into a fluorometer which outputs a voltage reading. This voltage can be back-referenced using a calibration curve to determine the concentration of Al in the original sample.
The next few weeks of my project consisted of using the autosampler I had programmed to determine the Al concentration of thousands of seawater samples obtained near volcanic sites. Aspects of this process became fairly repetitive, like cleaning plastic sample vials, preparing standard solutions, and pouring out samples, but much of the work was also gratifying. As I ran samples I realized ways I could improve my code to make sampling more efficient. During the first days of sampling I completed roughly 15 samples per day; by the end I was running 180 samples overnight. I used the data I acquired to construct concentration profiles that showed, for each volcano, how the Al concentration varied versus depth and latitude.
In my final weeks I worked on designing and testing a new method for determining Al content in seawater that would decrease the amount of waste produced. By only pumping reagent when needed, the new system would cut reagent waste to about one-tenth of what we produced using the flow injection system. It takes longer to run samples this way but the new method is environmentally friendlier, less expensive, and smaller, making it ideal for use on-board ships.
What made my project a success was getting to work on all aspects of seawater analysis, from apparatus design and computer automation to interpretation of results and development of new methods. In addition to my lab work I attended brown bag seminars, dropped in on NOAA socials, met tremendous scientists and learned about their work, explored a NOAA research ship and learned about life at sea, viewed live underwater dives on volcanoes off the coast of Indonesia, toured Seattle, and met great new friends. I owe this experience to JISAO and their excellent researchers and staff. I would highly recommend anyone looking for research experience in atmospheric or oceanographic sciences to give this program a try.
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