Bradley M. Bricker and Dr. Steven Wood, Chemistry and Biochemistry
It is the volatile aromatic compounds found in flowers that give them their distinctive aroma. These volatile compounds in their extracted form are often referred to as “essential oils.” And for thousands of years civilizations have been extracting these essential oils from flowers. There are many methods for obtaining these volatile compounds from flowers. Likewise, there are many intended purposes for the resulting extracts, ranging from aesthetic to medicinal.
In the past several centuries, the body of scientific knowledge concerning these volatile compounds has expanded significantly, from the efficacy of varying extraction techniques to the viability of various extracts for different purposes. It was the intent of this experiment to add to that body of scientific knowledge, and to do so in two specific ways.
First, we wanted to compare two common extraction techniques. These two techniques are enfleurage, a way of using lard and alcohol to extract the volatile compounds; and solvent extraction, a method employing a solvent (in our case hexane) to extract the compounds. By comparing the GC/MS results from these two extraction methods we planned to determine which method extracted more chemical compounds, as well as how the extracts from those two different methods differed chemically.
Second, we wanted to perform said extractions on two flowers for which we can find no previously recorded volatile constituent data. Those flowers are Freesia and Lathyrus.
We believe that we have empirically derived the answers we sought for our first goal. We have preliminary evidence of which method extracts more volatile compounds, and have observed trends that demonstrate how the extracts fundamentally differ. These results will be discussed shortly.
In regards to our second goal, to date the experiment is incomplete. While we have performed the extractions on Freesia—and are currently analyzing their implications—we are yet to obtain an extraction of Lathyrus. The reason for this will also be discussed shortly.
In order to ascertain our ability to obtain the desired volatile compounds, and to perfect our methodology, we performed some extractions previous to that of Freesia. Our first extraction was obtained from Lilac (Syringa ssp.). Our second and third extractions were obtained respectively from the blossoms and leaves of the Lavender plant (Lavendula ssp.). Again, the premise of these first three extractions was to determine and perfect our ability to obtain the desired extractions, hence the decision to use these particular flowers was merely an economic one.
These archetypal extractions were very successful, producing the GC/MS results on which we base our preliminary findings regarding our first goal. Specifically, it is our observation from the GC/MS that the lard/alcohol extractions tended to remove from the flowers more volatile compounds than the solvent extractions. Also, we have noted a tendency for the lard/alcohol extractions to remove from the flowers much longer, larger volatile molecules, as opposed to the shorter and smaller physical properties exhibited by molecules found via solvent extraction.
After performing the two extractions on the flowers of Freesia, we were unable to conclusively decipher the subsequent GC/MS results. We currently hypothesize that this is attributed to too dilute of an extract. We are trying to rectify the situation by increasing the concentration of our extracts in preparation for another GC/MS analysis.
Procurement of Lathyrus flowers for like purposes will remain pending either until we determine a solution for our current predicament with Freesia, or until scientific method renders the solution to our current predicament to be beyond our means of discovering.
Despite our current setback, we remain wholeheartedly optimistic about the progress that we have made in our research thus far. In terms of what we have collectively learned about the scientific method and about volatile compounds specifically, this research experiment may unequivocally be considered a success.