Pulsed field WATERGATE

Fig. 11. (A) A conceptual diagram of the WATERGATE subunit, the ir RF pulse is some type of selective tt pulse. (B) Multiple solvent suppression using the double-pulsed field gradient echo. Ihe selective ir pulses are SLP pulses to enable multiple solvent suppression. To avoid breakthrough of undesired coherences, different values for the gradients are used in the first and second echo. The phase cycling is given elsewhere. ...

Figure 9.27. Solvent suppression schemes employing pulsed field gradients based on (a) WATERGATE (single-echo) and (b) excitation sculpting (double-echo) principles. The pulse element S has zero net effect on the solvent resonance but inverts all others.

Figure 4 500 MHz NMR spectra of human blood plasma obtained using pulse sequences of (A) the double WATERGATE echo method and of (B) NOESYPRESAT under identical conditions. The low-field region is expanded and plotted as the inset. The labile proton resonances (marked by arrows) are observable in (A) but suppressed in (B) by saturation transfer effects.

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