NMR method. The new PSYCHE-iWG pulse sequence is shown in Figure , with more specific details provided in the Supporting Information (Figure ). The integration of WATERGATE (WG) into pure shift pulse sequences enables large solvent signals to be suppressed while solute signals are retained, even if in slow/medium chemical exchange with the solvent. Importantly, appropriate incorporation of the WATERGATE element into a pure shift sequence enables chemical shift evolution to be retained without any net contribution to homonuclear scalar coupling evolution from these elements. The overall scalar coupling evolution is therefore refocused as usual at the midpoint of the data chunk to be acquired. WATERGATE works by applying a zero net rotation to the on-resonance signal while off-resonance signals experience a 180° refocusing pulse. The PFGs flanking the WATERGATE element enforce the refocusing coherence transfer pathway (CTP), meaning that the on-resonance signal is dephased. The WG element achieves the desired effect using two low-power selective 90° pulses either side of a hard 180° pulse. The selective 90° pulses are on resonance for the solvent signal and leave the solute signals unaffected. The overall sequence uses a triple spin echo (TSE) structure in which the WG elements refocus offresonance signals, ensuring that timings remain balanced. The integration of two WATERGATE elements doubles the dephasing of the solvent signal, increasing the extent of solvent suppression. The chunk duration is equal to 1/SW1. τA controls the time at which J evolution is refocused during the chunk, and is equal to 1/4SW1. Shapes G1-4 represent field gradient pulses applied along z; G1, G2 and G4 are used for CTP selection and G3 is used for spatial encoding. Further details of the pulse sequence are given in the Supporting Information (Section A).