NMR is no longer under wraps
It looks like a rather fat, squat water heater. A water heater with a $743,000 price tag. But to the professors of PLU’s chemistry department, the nuclear magnetic resonance spectrometer is a dream come true. It’s easy to see they still can’t quite believe, after 2 years of waiting and receiving a National Science Foundation grant they didn’t expect to get, that it’s finally here. After being hidden behind tarps and plywood, it’s now in full display on the north side of a glass-walled laboratory at the Rieke Science Center on lower campus.“When the crates came,” said assistant professor of chemistry, Neal Yakelis, “we were very excited.”
The grant to purchase the NMR was a collaborative effort by chemistry faculty led by professor Craig Fryhle. The “science on display” glass enclosure was the idea of professor Dean Waldow.
Walking into the small room, the spectrometer is up and running. Already, Professors Waldow, Yakelis, and Fryhle, are analyzing samples with the NMR: Yakelis’s Organic Special Projects students and Waldow’s Instrumental Analysis students will be among the first students to use it.
The machine works by an electronic arm plucking out a sample from a rotating tray and slowly lowering it into a tube, which then goes down on a column of air into the bowels of the machine and into a center of a powerful magnet that is 200,000 times as strong as the Earth’s magnetic field. As the machine analyzes the sample, information starts appearing on the computer.
To an untrained eye, the readouts seem like random squiggles and blobs. But the frequencies mean quite a bit to the chemists. It tells them – on a molecular level – how atoms comprising a molecule are bonded together and what parts of the molecule are in motion with respect to the other parts of the molecule. On a more basic scale, it will help them decipher the compound they are looking at. Some solid samples need to spun inside the magnet at nearly the speed of sound to get the best data.
The spectrometer contains a series of chambers, with the outside chamber forming a vacuum jacket. The new chamber is then filled with liquid nitrogen, which is at a temperature of minus 321 degrees Fahrenheit. Inside the chamber, a superconducting magnet sits in a broth of liquid helium, which is even colder, at minus 452 degrees Fahrenheit, or just a few degrees above the lowest known temperature in the universe. The magnet is charged with electricity, which aligns the spins of the nuclei in a sample, thereby allowing it to be studied.
With regards to the magnet, visitors beware. Signs alert visitors to keep their credit cards, blackberries and cell phones at a safe distance. And if you have a pace maker, stay out. It will turn that off too. Getting too close to the machine means all will be erased.
Eventually, the group sees not only students using the machine for student-faculty research, but local community and four-year colleges bringing samples over as well. The Chemistry faculty plan to have webcasts from the NMR lab to teach local college and high school students about the NMR spectrometry.
Undergraduate students, who usually do not have access to such a powerful instrument, will find that having used the spectrometer-one of the first of its kind located in a West Coast undergrad institution – will help them land future jobs, the professors said.
“This is really going to be the crown jewel of the instruments in our department,” Waldow said when the team first learned the spectrometer was on its way to PLU.