Multiple quantum filtering
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Multiple quantum filtering is a method for purging 2D-correlation spectra from undesired signals, while keeping the favorite peaks. The method was introduced by Richard Ernst, U. Piantini and 0. W. Sorensen in 1982.
[edit] Protocol
Multiple quantum filtering can be achieved by the sequence:
90°(φ)-t1-90°(φ+ψ)-90°(ψ)-acquisition
For a p-quantum filter:
- Cycle the phase φ= kπ/p for k =0,1,2,..., 2p-1.
- Cycle the phase ψ for 0 and π/2.
- Add and subtract the resulting signals alternatively.
[edit] References
- U. Piantini, 0. W. Sorensen, and R. R. Ernst, J. Am. Chem. SOC. 1982, 104,68O0-6801.