The WATERGATE scheme is the most accepted building block to suppress the strong water resonance in NMR experiments of samples dissolved in H₂O. It is basically a water-selective spin echo building block and it is easily incorporated in the most of 2D, 3D, and 4D homo- and heteronuclear NMR experiments. It is usually applied as a 3-9-19 DANTE-based pulse train or using 90 water-selective pulses (The WG element).

Easy implementation on AVANCE spectrometers equipped with pulsed field gradients (PFGs).

For further details about implementation of WATERGATE scheme in AVANCE spectrometers see:

• Tutorial: The WATERGATE scheme.

See a list of available pulse programs containing the WATERGATE scheme with 3-9-19 and with the water selective 90 pulses.

The standard way to implement the WATERGATE scheme in a pulse program is using the 3-9-19 approach:

... 50u UNBLKGRAD p16:gp1 d16 pl0:f1 (p11:sp1 ph1:r):f1 4u d12 pl1:f1 (p2 ph2):f1 4u d12 pl0:f1 (p11:sp1 ph1:r):f1 46u p16:gp1 d16 4u BLKGRAD ...

in which:

• The selective 90 degree pulse applied on the water resonance is defined by the p11 (2 ms), sp1, and spnam1 (square) commands. The phase difference between hard and soft pulses must be carefully calibrated
• p16 (1ms), d16 (100u), gpz1 (20), gpz2 (20), gpnam1 (SINE.100), and gpnam2 (SINE.100) are gradient parameters defining PFGs. Typical values in parenthesis.
• All phase programs must be specified at the end of the pulse program.

See More info about WATERGATE ..

Other WATERGATE related approaches:

• 3919 element: Use of 3-9-19 DANTE-base pulse train
• es element: Excitation sculpting using 180 water selective pulse
• w5 element: Excitation scultping using high-power DANTE-based suppression