NMR for undergrads, continued
Guest Account (guest@kunmr.chem.ukans.edu)
Wed, 27 Sep 1995 12:22:06 -0500
AMMRL'ers,
I thought I might insert my $.02 on the subject of undergraduate
access to NMR lab instruments, since we have been doing this semi-
formally since 1991. Our solution to the large enrollment question raised
by Rich Shoemaker is to use a 100 position sample changer on our QE
Plus, an instrument purchased with NIH funds with an NSF ILI grant for
the sample changer itself. We teach the sophomore organic lab (the first
course where we use the instrument) TA's to load the sample changer
and log in the samples. The students get a TA-led demo of the real
instrument and spend about an hour in lab trying out a PC-based
simulation program of the QE menus (written by my colleage Ken
Ratzlaff). The enrollment in the spring semester lab is typically >250, but
there are never more than two sections of 30 students on any given day.
60 samples can be quite easily handled overnight. I wish they could get
on the real instrument, but it is difficult to imagine how to deal with 60
novice users at once in the last half hour of that lab. This spring, for the
first time, I have prevailed on the guy teaching the lab to include quick
COSY and HETCOR experiments (previously we have only done proton,
carbon, and DEPT), as he is young enough not to regard these
experiments as suspiciously new-fangled and impossible to explain.
The p-chem labs use the QE hands-on in both semesters, doing two
prehistoric experiments: keto-enol tautomerism, and determining the
coordination number and proton exchange rate of the aquo Al(III) ion
(an experiment I greatly admire, as a closet inorganic chemist).
Unfortunately neither of the experiments makes particularly effective use
of high field (if one can apply that term to 300 MHz), but the students
seem to like them--as one of our p-chem faculty puts it, at the very least
"it's not another damn bomb calorimetry experiment." The coefficient of
busy work reaches its semester-long nadir in these experiments and they
are actually somewhat fun. (I am continually amazed that none of them seem to
be cooking their data, since to the best of my knowledge nobody has ever
derived
a value of 6 for the coordination number of aluminum.)
In our ILI proposal, we told NSF we would use the instrument 10%
of the time for undergraduate instruction (including undergraduate
research). This use has not led to any complaints from the research users
of the instrument, in part because the bulk of the hours are expended at
night. We also have the benefit (though on days when I am cleaning up
after a smashed sample, I might not admit it) of the sample changer for
some research uses, e.g. quenched kinetics, titrations, and more recently,
combinatorial synthesis with a 72-head reactor. I am also hard pressed to see
how we could realistically use an instrument for instruction anything near 100%
of the time; by piggybacking on a research instrument we get a
substantial fraction of the pedagogical benefits without incurring the
fixed operating costs of an instrument dedicated to instruction.
With the exception of some samples broken by the GE sample
changer, which we have learned how to deal with, we have not had any
problems or breakdowns related to undergraduate use. The undergrads
doing research are by and large as apt as the graduate students,
sometimes more so, and I have no problem letting them use any of our
instruments, 500 included. There is a wider variation in skill for the
students in the lab courses, but those for whom the experience is like a
fish meeting a nuclear submarine tend to wait for the TA to come and
coach them. Nobody has, or is likely to, kick the probe to start the
experiment. In my experience undergrads generally have more respect
for the instrument than grad students do solely on the basis that it cost a
lot of money.
I believe there are real opportunities to enhance the undergraduate
curriculum with NMR. Can't everybody remember how much more
concrete the IR spectra of your own personal organic unknown were
compared with the spectra in the text or some yellowing atlas? If you
can make the leap of faith that the undergrads aren't bent on trashing
your instruments, it is possible to do the same thing with NMR. Hopefully one
of the satisfactions of running an academic lab is the chance to teach
what you know. Sure it takes time away from other stuff, for which neither a
raise or a medal seems very likely, but I have enjoyed it. Doing the QE
simulator was a particularly fun and offbeat sort of time-waster project, both
for me and for my colleague who sorted out doing all the operations in real
time, keeping the operations being faithfully simulated logically distinct from
those that were not, e.g. tutorial and help messages not supplied by the
instrument.
On a cautionary note, if your teaching labs are like
ours, most of what's in them is severely outdated and even the cheapest
NMR is more expensive than other useful and versatile alternatives, e.g.
tabletop GC/MS systems, lasers, or even, God forbid, a new computer
interfaced calorimeter. Also, if you have the idea of using undergraduate
instruction as a pretext for getting money for business as usual, you had
better be a pretty skilled liar since reviewers and adminstrators are
looking for that and may not be willing to be taken in.
So maybe I make Rich Shoemaker look concise by comparison ...
--
David Vander Velde, Director dave@kunmr.chem.ukans.edu
University of Kansas NMR Lab voice (913)864-4187
fax (913)864-5326