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PubMed · 12852919

Sensitivity-enhanced phase-corrected ultra-slow magic angle turning using multiple-echo data acquisition.

Jian Zhi Hu·Robert A Wind
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Abstract

The increase in the sensitivity of the phase-corrected magic angle turning (PHORMAT) experiment at ultra-slow spinning rates by means of multiple-echo data acquisition (ME-PHORMAT) is evaluated. This is achieved by replacing the acquisition dimension in the original experiment with a train of equally spaced pi-pulses. It is shown that the echoes following the odd and even pi-pulses in the CPMG train must be processed differently in order to avoid spectral distortions. The method is illustrated for 13C CP-ME-PHORMAT on solid 1,2,3-trimethoxybenzene and for 1H ME-PHORMAT on excised rat liver tissue, both at a sample-spinning rate of 1.3 Hz. Sensitivity enhancements of a factor 4 for the solid and 2.3 for the liver were obtained. Finally, it is shown that with ME-PHORMAT one of the two RF pulse sequences, in standard PHORMAT used to obtain a pure absorption mode 2D spectrum, can be eliminated, thus reducing the usually long measuring time by a factor 2.

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Jian Zhi Hu, Robert A Wind. 2003. Sensitivity-enhanced phase-corrected ultra-slow magic angle turning using multiple-echo data acquisition.. https://doi.org/10.1016/s1090-7807(03)00103-4

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