This school year, the Urban Honors program is offering some of its students a unique opportunity to obtain an in-depth look into chemistry and its real world application through a new Honors general chemistry class.
As part of this endeavor, Dr. Gwen Shusterman, the professor of the class, recently had the students execute a lab to see what kind of chemical traces, like cocaine, they could draw off of paper currency.
“I am really impressed; the class did really well,” Shusterman said.
The class tested several denominations of paper currency—$1, $20, and $100 bills—and when all was said and done, the chemical traces the students found included traces of cocaine, phthalates (used to make plastics soft), glycerine (most likely from hand lotion), urea (a chemical found in urine) and caffeine.
This is a chemistry class that is dealing with real life and urban problems, Shusterman said.
“The purpose of the lab was to analytically or quantitatively figure out how much of a chemical is present instead of just which chemical is present,” Shusterman said.
In a lecture given before the students analyzed their data in the lab, guest lecturer Dr. Jim Pankow, whose lab the students used to run their experiment, explained how besides the traces of cocaine found, the phthalates located are also something to be studied.
“Studies have found these plasticizers, these phthalates, along with BPA, as the cause of some fertility problems,” Pankow said.
The lab, entitled “Extraction and analysis of paper currency: Introduction to analytical principles of gas chromatography/mass spectrometry,” was based on a government case study published in Alabama that suggested that finding chemical traces of methamphetamine on paper currency in an area could indicate an increase in a methamphetamine use and production.
This means that by testing paper currency for chemical traces of compounds found in illegal drugs such as cocaine and methamphetamine, officials ideally would be able to pinpoint where the use and manufacturing of these drugs will become a problem.
Being an Urban Honors seminar, part of the class’s purpose is to put chemistry into real world problems, Shusterman said.
“We’re trying to balance fundamentals with things the students haven’t done before.”
In his lecture, Pankow explained that what the students were performing was open tube gas chromatography. He also had the students perform a simple experiment in class to demonstrate the principles involved in chromatography.
Each student was given a plastic cup, a piece of tape and a small slip of paper with a green marker dot on it. Students taped the paper to a pen or pencil and laid it across the top of the cup after pouring a small amount of water into the bottom of the cup—just enough so the very bottom of the strip of paper touched the water, but not enough to cover the green dot. Within a minute, the water wicked up into the strip of paper, causing the marker dot to bleed and streak into different colors.
This experiment showed the two phases of chromatography—the mobile and stationary phases.
The lecture continued by informing students that in their lab they would be able to figure out the identities of the different chemical traces they had found by the weight of the molecules in each chemical. Urea, for example, has a very light molecular weight, which can make it difficult to test for.
Pankow said he hoped the students would be able to identify not only cocaine but one or two other compounds as well in their data analysis and gave examples of the chromatograms the students would be using.
“The students will view their chromatograms on the computer so they can analyze their data and check to see what additional compounds were found in the samples,” Pankow said.
Dominic Galen, a freshman Honors student studying environmental engineering, explained the step-by-step process the students performed in the beginning of the lab.
“We put the bill in a tube, put in the solution containing the solvent, then extracted certain amounts from the tube into a vial, and Dr. Pankow ran the samples,” Galen said.
Freshman Honors student Alyssa Clayton, who is taking pre-med classes but hasn’t decided on her major, explained that the actual running of the samples was a very time-consuming process.
“I think each sample took about an hour, over a period of three days,” Clayton said.
Both Galen and Clayton agreed that they were drawn to the class due to the more in-depth chemistry they’d be studying, as well as the smaller class size.
Shusterman said the class is an exciting opportunity for students since it’s a smaller seminar.
“We couldn’t have done this lab in a regular general chemistry class due to the class size and how long it took to run the samples in the lab,” Shusterman said.
The seminar is not a required honors seminar but does fulfill degree requirements for students pursuing science-based degree programs.