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the silica tube wall with a drop of epoxy cement, and held under constant tension. The wire was then
slowly wound on the tube by gentle rotation and finally secured with more epoxy cement. The epoxy
cement does cause line broadening, but its effect was minimized by only using a very small quantity at
the ends of the coil. The impedance matching capacitors also have some susceptibility, and to reduce
any broadening effect that might result, they are placed at opposite ends of the 3 cm length of coaxial
cable.

Figure 13.38
A Two-dimensional Presentation of the Separation of Some Amino Acids
Employing the Capillary Electrophoresis/NMR Spectrometer Tandem System
Reprinted with permission from N. Wu, T. L. Peck, A. G.Webb, R. L. Magin
and V. Sweedler, Anal. Chem., 66(22)(1994)3849
Copyright 1994 American Chemical Society.

The micro-coil assembly was mounted in a modified NMR probe and oriented so that the coil was
perpendicular to the static magnetic field over the detection region. In order to avoid interference and
damage from the high voltages necessary in capillary electrophoresis, the potentials used were kept
below the breakdown voltage of the silica tube in the sensor volume section. The NMR spectrometer
that was employed was the GN300(7.05T)/89 mm, and the capillary electrophoresis system was
situated in an acrylic enclosure at the end of the NMR probe. The reduction in