Nearly 106-fold enhancements in intermolecular 1H double-quantum NMR experiments by nuclear hyperpolarization
Nearly 106-fold enhancements in intermolecular 1H double-quantum NMR experiments by nuclear hyperpolarization
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DOI：
10.1016/j.jmr.2009.06.002
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发表时间：
2009-09-01
影响因子：
2.2
通讯作者：
Frydman, Lucio
中科院分区：
文献类型：
--
作者：
Mishkovsky, Mor;Eliav, Uzi;Frydman, Lucio
分子间多量子相干（iMQCs）可以产生有趣的NMR信息，在光谱学和成像中具有很高的潜在用途-前提是可以克服其相关的灵敏度限制。最近的一项研究表明，非原位动态核极化（DNP）可以帮助克服基于iMQC的C-13核实验的灵敏度问题。在目前的工作中，我们表明，一个类似的方法是可能的，当针对质子的超极化溶剂。发现尽管DNP过程将单量子H-1信号增强了约600，这显著小于优化的低伽马液态对应物，但iMQC衍生的信号对偏振的非线性依赖性可以产生非常大的增强，接近10（6）。显然，没有实际量的数据平均可以匹配这种灵敏度增益。事实上，DNP赋予iMQC为基础的H-1 NMR光谱的灵敏度，大大超过了他们的热极化单量子对应物，在一些简单的单扫描2D成像实验证实。(C)2009 Elsevier Inc. All rights reserved.
Intermolecular Multiple-Quantum Coherences (iMQCs) can yield interesting NMR information of high potential usefulness in spectroscopy and imaging - provided their associated sensitivity limitations can be overcome. A recent study demonstrated that ex situ dynamic nuclear polarization (DNP) could assist in overcoming sensitivity problems for iMQC-based experiments on C-13 nuclei. In the present work we show that a similar approach is possible when targeting the protons of a hyperpolarized solvent. It was found that although the DNP procedure enhances single-quantum H-1 signals by about 600, which is significantly less than in optimized low-gamma liquid-state counterparts, the non-linear dependence of iMQC-derived signals on polarization can yield very large enhancements approaching 10(6), Cleary no practical amount of data averaging can match this kind of sensitivity gains. The fact that DNP endows iMQC-based H-1 NMR spectra with a sensitivity that amply exceeds that of their thermally polarized single-quantum counterpart, is confirmed in a number of simple single-scan 2D imaging experiments. (C) 2009 Elsevier Inc. All rights reserved.