KTH Royal Institute of Technology, Physical Chemistry, Teknikringen 36, 10044, Stockholm, Sweden.
Eur Biophys J. 2013 Jan;42(1):25-32. doi: 10.1007/s00249-012-0794-8. Epub 2012 Feb 21.
Pulsed gradient spin-echo (PGSE) NMR techniques have found growing and widespread use for investigation of a variety of physicochemical phenomena in solution, because of their effect on molecular self-diffusion, and for primarily analytical purposes, for example separation of overlapping NMR bandshapes obtained from multi-component samples. A multi-component spectral separation approach previously introduced by the author (named CORE) is founded on the fact that each part of a molecule diffuses at the same rate, and thus PGSE NMR signals from each functional group will attenuate in a fully concerted fashion throughout a PGSE experiment. Numerical separation and analysis of component NMR spectra by CORE processing is therefore stabilized and steered by this prior knowledge constraint. However, even with two components and with similar self-diffusion rates, numerical instability and cross-talk between similar component self-diffusion may appear even with good experimental signal-to-noise ratio and only minor or no component spectral overlap. So-called RECORD processing was recently introduced to accompany the CORE method. In this more robust variant, spectra are divided into several sub-regions that are treated separately and combined in a later stage. The rationale for and advantages of the generic RECORD-based approach are further discussed and illustrated. A further hybrid CORE processing variant named GRECORD is suggested and briefly tested.
脉冲梯度自旋回波 (PGSE) NMR 技术因其对分子自扩散的影响，以及主要用于分析目的，例如分离来自多组分样品的重叠 NMR 谱带形状，在溶液中各种物理化学现象的研究中得到了越来越广泛的应用。作者之前引入的一种多分量谱分离方法（称为 CORE）基于这样一个事实，即分子的每个部分以相同的速率扩散，因此 PGSE NMR 信号将在整个 PGSE 实验中以完全协调的方式衰减。因此，通过 CORE 处理对各个组成部分 NMR 谱的数值分离和分析受到这种先验知识约束的稳定和引导。然而，即使对于两个成分，并且具有相似的自扩散率，即使具有良好的实验信噪比，并且仅存在较小的或没有成分光谱重叠，也可能会出现数值不稳定性和相似成分自扩散之间的串扰。最近引入了所谓的 RECORD 处理来伴随 CORE 方法。在这种更稳健的变体中，谱被分成几个子区域，这些子区域分别进行处理，并在稍后的阶段组合。进一步讨论和说明了基于 RECORD 的通用方法的原理和优势。还提出并简要测试了一种名为 GRECORD 的进一步混合 CORE 处理变体。
