Pre-SAT180, a simple and effective method for residual water suppression

Water located outside the NMR detection coil experiences a reduced RF field intensity. This “faraway water” is known to be very difficult to suppress and often gives rise to a large residual solvent signal. Pre-SAT180 (Pre-Saturation with Adiabatic Toggling of 180 degree pulse inversion) is proposed to cancel the residual water contribution efficiently. Compared with several popular methods such as 1D NOESY with pre-saturation or 270° excitation, Pre-SAT180 has a number of advantages, including: full retention of signal intensity and selectivity, good phase properties, easy setup, and high tolerance to pulse missettings.