Dipolar cross-relaxation modulates signal amplitudes in the 1H NMR spectrum of hyperpolarized [13C]formate
Dipolar cross-relaxation modulates signal amplitudes in the 1H NMR spectrum of hyperpolarized [13C]formate
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DOI：
10.1016/j.jmr.2007.09.011
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发表时间：
2007-12-01
影响因子：
2.2
通讯作者：
Sherry, A. Dean
中科院分区：
文献类型：
--
作者：
Merritt, Matthew E.;Harrison, Crystal;Sherry, A. Dean
与超极化（13）C耦合的自旋双重态中的不对称性先前已被用于测量（13）C的初始极化。我们测试了一个假设，即单次观察超极化（13）甲酸C的(1)H NMR谱就能监测（13）C极化。根据极化过程中微波频率的不同，在(1)H核磁共振谱中可以观察到相内或相外双重态。即使在这个简单的双自旋体系中，由于强异核交叉弛豫，（13）C极化也没有反映在J（CH）双重态组分的相对面积上。利用Solomon方程将质子信号建模为极化后时间的函数，并从(1)H NMR谱估计（13）C极化。(c) 2007爱思唯尔公司版权所有。
The asymmetry in the doublet of a spin coupled to hyperpolarized (13)C has been used previously to measure the initial polarization of (13)C. We tested the hypothesis that a single observation of the (1)H NMR spectrum of hyperpolarized (13)C formate monitors (13)C polarization. Depending on the microwave frequency during the polarization process, in-phase or out-of-phase doublets were observed in the (1)H NMR spectrum. Even in this simple two-spin system, (13)C polarization was not reflected in the relative area of the J(CH) doublet components due to strong heteronuclear cross-relaxation. The Solomon equations were used to model the proton signal as a function of time after polarization and to estimate (13)C polarization from the (1)H NMR spectra. (c) 2007 Elsevier Inc. All rights reserved.