Self-Correcting Method for the Measurement of Free Calcium and Magnesium Concentrations by 1H NMR.
Self-Correcting Method for the Measurement of Free Calcium and Magnesium Concentrations by 1H NMR.
复制标题
通过 1H NMR 测量游离钙和镁浓度的自校正方法。
DOI：
10.1021/acs.analchem.9b03008
复制
发表时间：
2019
影响因子：
7.4
通讯作者：
Wallace M
中科院分区：
文献类型：
--
作者：
Wallace M
本文介绍了一种用核磁共振光谱法直接测定1 ~ 100mm范围内游离Ca2+和Mg2+浓度的方法。该方法自动校正离子强度对溶液中物种活性的影响，即使存在显著浓度的竞争离子，也能令人满意地工作。该方法只需要测量我们的报告配体，乙醇酸和乙酸磺酯的1h化学位移，并且很容易使用核磁共振成像技术实现。作为概念的证明，我们使用原位离子梯度提取了分析物配体的热力学结合常数和构象分布。现有的通过核磁共振测量游离Ca2+或Mg2+浓度的方法只能在非常低的离子浓度下操作，否则需要根据不同的样品条件仔细重新校准。通过提供游离Ca2+或Mg2+浓度，所提出的方法显着增强了通过离子响应系统的核磁共振研究获得的信息。
A method for the direct measurement of free Ca2+and Mg2+concentrations in the range of 1–100 mM by NMR spectroscopy is demonstrated. The method automatically corrects for the effect of ionic strength on the activity of the species in solution and works satisfactorily even when significant concentrations of competitive ions are present. The method requires only the measurement of the1H chemical shifts of our reporter ligands, glycolate and sulfoacetate, and is easily implemented using NMR imaging techniques. As a proof of concept, we extract the thermodynamic binding constants and conformer distributions of analyte ligands using an in situ ion gradient. Existing approaches for the measurement of free Ca2+or Mg2+concentrations by NMR operate only at very low ion concentrations or else require careful recalibration for different sample conditions. By providing the free Ca2+or Mg2+concentrations, the proposed methodology significantly enhances the information obtainable via NMR investigations of ion-responsive systems.