Chen Xi, Lin Meijin, Chen Zhong, Cai Shuhui, Zhong Jianhui
Department of Physics, State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen, 361005, PR China.
Phys Chem Chem Phys. 2007 Dec 21;9(47):6231-40. doi: 10.1039/b709154k. Epub 2007 Oct 16.
Intermolecular zero-quantum coherences (iZQCs) are not susceptible to magnetic field inhomogeneities significantly larger than the dipolar correlation distance and can be used to obtain 1D high-resolution spectra in an inhomogeneous field. However, with the iZQC methods proposed previously, residual conventional single-quantum coherences (SQCs) originating mainly from solvent resonance result in strong t(1) ridge noises. A modified HOMOGENIZED with an intermolecular double-quantum filter (iDQF), named iDQF-HOMOGENIZED, is presented in this work to suppress the residual conventional SQC signals as well as solvent iZQC signals. The solvent-suppression efficiency of the iDQF-HOMOGENIZED is analyzed and a thorough comparison of the new sequence with several relevant pulse sequences is made. Dramatic resolution enhancement and solvent suppression in the measurements of a piece of grape sarcocarp suggest potential applications of the method in in vivo spectroscopy.
分子间零量子相干（iZQCs）对远大于偶极相关距离的磁场不均匀性不敏感，可用于在非均匀场中获得一维高分辨率光谱。然而，采用先前提出的iZQC方法时，主要源于溶剂共振的残留传统单量子相干（SQCs）会导致强烈的t(1)脊噪声。本文提出了一种用分子间双量子滤波器（iDQF）改进的HOMOGENIZED，即iDQF-HOMOGENIZED，以抑制残留的传统SQC信号以及溶剂iZQC信号。分析了iDQF-HOMOGENIZED的溶剂抑制效率，并将新序列与几个相关脉冲序列进行了全面比较。在一片葡萄果肉的测量中，分辨率显著提高且溶剂得到抑制，这表明该方法在体内光谱学中具有潜在应用。
