Read the original story here in The Oregonian.
Students in a Portland State University freshman chemistry class recently donned white lab coats, protective ear gear and latex gloves for a morning of sleuthing.
Much like forensic scientists that investigate crime scenes, these students were looking for chemical residues on money. What they found is that bills are dirty, tainted with everything from drugs and plastics to traces of urine.
The most common substance was cocaine. It turned up on all but one of the U.S bills the students tested, from a $1 note to $100. But it was not detected on a 20-rupee note that one student brought in. Instead, the rupee had residues ofglycerine, which is a sign of hand lotion, as well as cholesterol and phthalates, compounds used to make plastics.
Glycerine and phthalates were found on several U.S. bills, too, along with nicotine and urea, an indication of urine.
Perhaps the most surprising result: The students tested for caffeine but found no traces of Portland's favorite pick-me-up.
Jim Pankow, a PSU chemistry professor, suspects there was caffeine on the bills but that the students just didn't find it.
"It seems suspect to me that there wasn't caffeine on the bills," he said.
But more than the results the experiment was about method: The students relied on the same high-tech equipment that are used in forensic labs to find traces of blood and drugs.
"These are the methods that are used to convict criminals," Pankow said.
-- Lynne Terry