Easy implementation on AVANCE spectrometers.

The standard way to implement the reverse-INEPT block incorporating a WATERGATE scheme in a 1H-15N experiment is:

... (p21 ph1):f3 (p1 ph2) 50u UNBLKGRAD p16:gp1 d16 pl18:f1 p27*0.231 ph3 d19*2 p27*0.692 ph3 d19*2 p27*1.462 ph3 d19 (p22 ph5):f3 d19 p27*1.462 ph4 d19*2 p27*0.692 ph4 d19*2 p0*0.231 ph4 46u p16:gp2 d16 4u BLKGRAD ...

in which:

• pl18 is the power level for 3-9-19-pulse from the f1 channel
• p27is the 90 degree pulse at pl18. The same value is used for p0 which is used for fine adjustment.
• d19 is the delay for binomial water suppression. Sidebands must be carefully avoided from the distance (d) of next null (in Hz) (1/(2*d).
• 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.