Summary: HMQC vs HSQC and AMX display replacement

Kirk Marat (kirk_marat@umanitoba.ca)
Thu, 6 May 1999 14:01:49 -0400

A while ago I initiated some discussion on the relative merits of
HMQC vs. HSQC, being somewhat surprised at the number
of users preferring HMQC. From the replies I got, It seems that
HMQC is more tolerant of non-ideal conditions (non-inverse probe,
pulses mis-calibrated, probe mis-tuned, etc.) and therefore may be easier
to use
on a routine basis. HSQC, on the other hand, gives better F1 resolution
and usually better sensitivity - probably because of the better F1
resolution.
On our AMX 500 I always uses HSQC, but I do take the time to check the
probe tuning and proton pulse calibration (unless I've just run a sample
in the same solvent), and we are using inverse probes.

I had also inquired about the possibility of using a standard multi-sync
PC display as a replacement for the console display on our AMX500
with an X32. I got a number of replies concerning AM/AC monitor
replacement and monitors for SGIs and ASPECT stations, but none
for X32's. Well, I guess I just have to kludge together a cable and
try it!

Some suggested that NMR vendors are supplying special shielded monitors.
I'm not so sure that they are. The monitors supplied with SGI and Sun
computers
are just standard Sony monitors (with Sony model numbers). Bruker did
supply one
monitor (called an EIZIO ??) that did seem somewhat less prone to the
"rainbow" effect. I think most of the shielding for our AM and AMX monitors
actually
comes from the console cabinetry itself. The left end of our AMX500 sits
very
close to a 360 WB magnet and the only way to get a decent display was to
line the
left end of the cabinet with about 4 layers of mu metal.

On a similar theme, has anyone tried one of the new flat panel LCD displays
on an NMR system? Decent ones are somewhat expensive, but that would solve
the shielding problems!

Cheers,
-Kirk

Kirk Marat, Ph.D. NMR Facility Manager
Dept. of Chemistry and Prairie Regional NMR Centre
University of Manitoba
Winnipeg, Manitoba, R3T 2N2, CANADA
ph. (204) 474-6259 FAX (204) 474-7608
kirk_marat@umanitoba.ca