Enhancing MQMAS sensitivity using signals from multiple coherence transfer pathways

Zhehong Gan; Hyung-Tae Kwak

doi:10.1016/j.jmr.2004.03.021

Enhancing MQMAS sensitivity using signals from multiple coherence transfer pathways

J Magn Reson. 2004 Jun;168(2):346-51. doi: 10.1016/j.jmr.2004.03.021.

Authors

Zhehong Gan¹, Hyung-Tae Kwak

Affiliation

¹ National High Magnetic Field Laboratory, Center of Interdisciplinary Magnetic Resonance, Tallahassee, FL 32310, USA. gan@magnet.fsu.edu

PMID: 15140446
DOI: 10.1016/j.jmr.2004.03.021

Abstract

Multiple-quantum magic-angle spinning experiment removes second-order quadrupolar broadening from the central-transition of half-integer quadrupolar nuclei. This paper presents a novel scheme to enhance the sensitivity of MQMAS using signals from multiple coherence transfer pathways. The enhancement can be obtained in two ways. The first method uses the multiplex phase cycling to acquire MQMAS spectra from various coherence transfer pathways simultaneously. An addition of spectra collected with no extra time enhances the efficiency of the experiment. The second method, soft-pulse-added-mixing, is designed based on a complete alias of coherence transfer pathways. By properly fixing the soft-pulse phase, signals from various coherence transfer pathways can add constructively resulting higher signal intensities. The two methods are demonstrated for sensitivity enhancement with samples of spin-3/2 and 5/2.