A new microtechnique has been developed which is particularly suited for running microsamples in sealed capillary tubes. The capillary holder, a modified coaxial cell, simplifies the operation by eliminating the cumbersome use of capillary positioning devices. In cases where an external lock is used, the lock material can be permanently sealed between the walls of the coaxial tubes. Gas chromatography fractions can be collected directly in the capillary tubes. Consequently, sample transfer is eliminated and the possibility of sample loss and contamination is reduced. Excellent NMR spectra can be obtained in a single scan experiment from as little as 1 mg of sample. By using a time average computer in conjunction with the microtechnique and averaging for 100 scans, a good spectrum from 100 μg is possible.
Louis V. Haynes and Charles D. Sazavsky, "A New NMR Microtechnique," Appl. Spectrosc. 24, 452-454 (1970)