The Study On Solvent Resonance Suppression Method In Liquid NMR

Solvent resonance suppression is one of the important techniques in NMR spectroscopy, especially in biological NMR studies. In the past decades, a number of methods have been developed and applied. This thesis focuses on studying the properties and applicability of WATERGATE method.The composite pulse trains for frequency selection in W3, W5, double WATERGATE W3 (DW3) and double WATERGATE W5 (DW5) must make water resonance a 0?flip angle. Otherwise, The flip angle error may have significant influence on various WATERGATE suppression effects. The strong desire to apply these methods conveniently incites us to investigate their sensitivity to the pulse width error. In addition, the experimental results are verified theoretically by the simulation calculation.Although DW5 is an effective water suppression technique, there were small phase distortions observable in its spectrum due to the large J coupling constants. The distortions have been removed by incorporating spin-lock pulse and Z-filter into DW5 sequence.DW5 is applied dierctly into 2D COSY and 2D J-resolved spectra in the last chapter, and RECUR is applied further into 2D correlation spectroscopy for recovering the resonances close to or under water. It is demonstrated that DW5 is still an effective method in the 2D NMR.