The contact is:
Shigemi, Inc.
4790 Route 8 Suite 21
Allison Park, PA 15101-2459
Phone: 412-444-3011
FAX: 412-444-3020
We have had excellent results with these tubes on our Varian 500 & 600
systems. They are available in 3mm & 5mm OD sizes matched to the
susceptibility of water, DMSO, and CHCl3. In addition to providing a
concentration boost for all samples, the removal of solvent from above
and below the receiver coil provides a tremendous increase in the
quality of water suppression for 90%H2O samples.
We have used 3mm and 5mm cells matched to water for CHCl3, with fairly
good results, but we eventually purchased one of each susceptibility
value for the facility. For solvents other than the three above, we use
the one corresponding to the solvent whose magnetic susceptibility most
closely matches that of the actual sample. In our experience, too great
a difference decreases the best attainable lineshape & makes shimming
difficult. In general, we have come to expect a large change in Z4 for
between these tubes and a conventional tube, no matter what the
tube-solvent match is.
When I ordered last June, the tubes ranged between $72 and $85 each,
depending on the size and solvent matched.
N.B.: Be sure to specify the probe type they are to be used with (with
my order the choices were Varian or Bruker)--it makes a difference in
the thickness of the bottom cell. Apparently one of the probe designs
has has a shorter coil-to-probe bottom depth so the tubes are not
interchangeable between the vendors probes if you want optimum
performance. (You can guess how we found this out.)
--Also, be sure to ask for the instructions on removing air bubbles.
They will save you a lot of time!
-- Dean V. Carlson, Ph.D. Director of NMR Services Purdue University Department of Chemistry carlson@purdue.edu
Tim Claridge wrote: > > Dear All, > > I have seen in a recent JMR paper reference to (5 mm) Shigemi tubes and > inserts that are susceptability-matched to chloroform. I have heard of such > tubes matched to water before, but not to chloroform. Could someone please > provide me with a contact address for Shigemi (preferably email or WWW), or > does anyone know of a supplier of Shigemi tubes in the UK? > > If anyone has any experience with these tubes in the handling of small > sample quantities (volumes), I would also be interested to hear from you. > > With thanks, > > Tim. > > Dr. Tim Claridge > NMR Facility Manager > The Dyson Perrins Laboratory > University of Oxford > South Parks Road > Oxford OX1 3QY, UK. > Tel: (01865) 275658 Email: tim.claridge@dpl.ox.ac.uk > Fax: (01865) 275674