Monday, December 7, 2009

Stormy Weather

It's the rainy season, and I'm gonna bitch about it. I rode to school today, on my road bike, ending up soaked and dirty. On the bright side, I wore black and I look good wet.

Life has been stormy, too. I've just attended the Southern California Users of Magnets (SCUM) meeting, which was co-hosted by my research advisor, mentor, and personal hero, Professor Cynthia Larive and my husband's former research advisor, Professor Len Mueller. It was sponsored (in part) by the company my husband interviewed with in Boston last month, Bruker. I feel like I have a million projects going on right now and it's only a matter of time before I screw something up. But it's all about perception, right? And for now it seems I am managing.

I've been developing some educational materials for a course called "Instrumental Methods," which involves advanced topics in analytical chemistry, such as; chromatographic separations, electrochemistry, and spectroscopic techniques. Analytical chemists are known for attention to detail, accuracy & precision, and the desire to know (1) What substance(s) are present in a "sample" and (2) How much (of each substance) is present in the "sample." One could make a career as an analytical chemist improving experimental designs for targeted analysis or validating new methods to enhance the richness of information from a nontargeted analysis. Often, the analytical chemist is challenged to balance performance and cost, lending somewhat of an engineering or applied type of problem-solving to our field. We can also see a direct application of our work in many diverse types of fields: environmental monitoring, medical devices, pharmaceutical R&D pipeline, quality control, drug enforcement, etc.

Speaking of which, the reason I'm developing these new educational materials [namely a problem-based laboratory exercise] is because UCR Department of Chemistry was the recipient of a Gas Chromatograph-Mass Spectrometer (GC-MS) donated kindly by the local Drug Enforcement Agency (DEA) lab. It's cool because it's already set up to detect small amounts of volatile organic molecules in a complex mixture, because it was likely used to detect banned substances and their downstream metabolites in urine, feces or blood.

The class of substances we're focusing on in this activity are monoterpenes. These are found in citrus peel (among other plant-based sources) and are useful for cleaning and degreasing (as in the case of turpentine) and/or for fragrances in perfumes and soaps. I have isolated monoterpenes from a variety of citrus fruits, including orange, lime and lemon, tangerine and mandarin so far. Each peel has offered a complex mixture of these molecules (between 5 to 20 detectable monoterpenes per variety of citrus) and the subtle but statistically significant differences between fruits is what we're interested in recording.

Since my other research advisor, Julia Bailey-Serres, has been training me to think like a plant biologist, I asked the question "But why does the plant produce these compounds?" Surely not for us to use as a degreaser or additive to our soaps and perfumes. It turns out that these molecules have exhibited antifungal activity in addition to deterring insects from the area. This protects the fruit from pathogen attack and allows the citrus to live long and prosper.
I found limonene in high abundance in each peel extract, while the relative amounts of the minor components in each extract were variable. Orange and Tangerine peels contained little or no beta-pinene, both Lemon and Lime peel contained more beta- than alpha-pinene, and the relative amount of beta-myrcene correlated with strong and pleasant aromas (using the human nose detector that I have built-in for cross-validation). This makes good sense since myrcene is one of the most important chemicals used in the perfumery industry.
So as you can probably tell I'm still trying to find some footing for this lab, but I think it's coming along well so far. It's got to be ready to go in January when classes start (week of Jan 5, 2010) which is less than 4 weeks. This project, along with my regularly scheduled research and another educationally-related project (that I haven't even brought up here yet) is keeping me very busy. Oh yeah and I forgot to mention, we're moving to San Diego. But as I said, I'm managing. I have so many wonderful people in my life right now. Thank you all for your support.