Department of Physics, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, PR China.
Appl Spectrosc. 2010 Feb;64(2):235-40. doi: 10.1366/000370210790619645.
A new pulse sequence based on intermolecular single-quantum coherences (iSQCs) is proposed to achieve high-resolution two-dimensional (2D) J-resolved spectra in inhomogeneous fields via three-dimensional (3D) acquisition. Since the iSQC evolution period and spin echo evolution period in this sequence are intrinsically insensitive to magnetic field inhomogeneities, high-resolution 2D J-resolved spectra can be recovered from nuclei in inhomogeneous fields by projecting the 3D data onto the 2D plane. Analytical expressions of the resulting signals were derived assuming the secular dipole-dipole interaction. Analyses of a solution sample placed in a deliberately unshimmed magnetic field and of a biological sample with intrinsic field inhomogeneities were performed. The results show that this sequence provides an attractive and efficient way to eliminate the influence of field inhomogeneities on 2D J-resolved spectra, which is potentially useful for characterizing complex chemical materials and studying biological metabolites in inhomogeneous fields.
提出了一种基于分子间单量子相干（iSQC）的新脉冲序列，通过三维（3D）采集在非均匀场中实现高分辨率二维（2D）J 分辨谱。由于该序列中的 iSQC 演化期和自旋回波演化期对磁场不均匀性本质上不敏感，因此可以通过将 3D 数据投影到 2D 平面上来从非均匀场中的核中恢复高分辨率 2D J 分辨谱。在假设瞬态偶极-偶极相互作用的情况下，推导出了所得信号的解析表达式。对置于故意未匀场的溶液样品和具有固有磁场不均匀性的生物样品进行了分析。结果表明，该序列为消除磁场不均匀性对 2D J 分辨谱的影响提供了一种有吸引力且有效的方法，这对于表征复杂化学材料和在不均匀场中研究生物代谢物可能非常有用。
