Increasing NMR signal sensitivity of samples containing high salt concentration

A supplementary solution for increasing NMR signal sensitivity of samples containing high salt concentration, by reducing back ground signal noise.

There is a great article by Alexander E. Kelly, Horng D. Ou, Richard Withers, and Volker Dötsch titled “Low-Conductivity Buffers for High-Sensitivity NMR Measurements”, J. Am. Chem. Soc., 124 (40), 12013 -12019, 2002. 10.1021/ja026121b S0002-7863(02)06121-8 Web Release Date: September 13, 2002 Copyright © 2002 American Chemical Society , that demonstrates that salt concentration alone is not the decisive factor in controlling background noise levels created by high salt matrixes, but that concentration and ion mobility together need to be considered in reducing noise levels.

Many researchers have approached us with the need to have less sample volume, after adjusting to a new buffer, to take advantage of this effect. For changing sample volume, we are offering our customers several solutions. One option is to use our 5mm thick walled (1.4mm wall) NMR tube, which has a 0.19ml fill volume compared to the 0.71ml fill volume of our standard 0.38mm wall tube at 50 mm sample height. The second option involves using a new special spinner insert adaptor that holds either 4.25mm, 4.00mm, 3.00mm, 2.50mm, 2.00mm, 1.70mm, and 1.00mm NMR tubes in a 5mm spinner turbine. We have adaptors for both stock Bruker and Varian spinner turbines, and good NMR signal has been reported even when using a 1mm NMR tube with a 5mm cryo-probe. The advantage of using the Norell spinner insert, is that you do not need to purchase or have specially made spinners for the complete selection of NMR tube sizes. You can now determine very easily the tube size that performs optimally for the type of sample and sample volume that is called for in the experiment.

Call the Norell customer service department for more details on how to use the new inserts.