Does It Bind? A Method to Determine the Affinity of Calcium and Magnesium Ions for Polymers Using (1)H NMR Spectroscopy.
Does It Bind? A Method to Determine the Affinity of Calcium and Magnesium Ions for Polymers Using (1)H NMR Spectroscopy.
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DOI：
10.1021/acs.analchem.2c01166
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发表时间：
2022-08-09
影响因子：
7.4
通讯作者：
Hussain, Haider
中科院分区：
文献类型：
--
作者：
Wallace, Matthew;Holroyd, Joshua;Kuraite, Agne;Hussain, Haider
钙和镁离子（M2+）通过聚合物和其他大分子在水溶液中的结合在化学和生物学中是普遍存在的。目前，如果不借助电位滴定和/或等温滴定量热法，很难评估大分子对M2+的结合亲和力。这两种技术都需要专门的设备，而且测量结果很难执行和解释。在这里，我们提出了一种基于1H核磁共振化学位移成像（CSI）的新方法，该方法可以在标准高场核磁共振设备上的单个实验中评估聚合物的结合亲和力。在我们的方法中，将M2+乙酸盐称重到一个标准的5毫米核磁共振管中，并在上面分层聚合物溶液。盐的溶解和扩散带着M2+和醋酸盐离子穿过溶液。用CSI在样品的不同位置测量乙酸[Ac]和游离（未结合）M2+ [M2+]f的浓度。M2+与聚合物的结合降低了[M2+]f，阻碍了M2+向上扩散。因此，在[Ac]和[M2+]f之间观察到一个差异，从中可以评估聚合物的结合亲和力。对于与M2+形成不溶性配合物的体系，如聚丙烯酸钠或羧酸功能化纳米纤维素（CNC），我们可以确定聚合物沉淀的M2+浓度。我们还可以预测当聚合物溶液与M2+盐均匀混合时的[M2+]f。我们评估了聚丙烯酸钠、海藻酸盐、聚苯乙烯磺酸盐、CNC、聚乙烯亚胺、乙二烯四乙酸和马来酸盐的结合性能。
The binding of calcium and magnesium ions (M2+) by polymers and other macromolecules in aqueous solution is ubiquitous across chemistry and biology. At present, it is difficult to assess the binding affinity of macromolecules for M2+ without recourse to potentiometric titrations and/or isothermal titration calorimetry. Both of these techniques require specialized equipment, and the measurements can be difficult to perform and interpret. Here, we present a new method based on 1H NMR chemical shift imaging (CSI) that enables the binding affinity of polymers to be assessed in a single experiment on standard high-field NMR equipment. In our method, M2+ acetate salt is weighed into a standard 5 mm NMR tube and a solution of polymer layered on top. Dissolution and diffusion of the salt carry the M2+ and acetate ions up through the solution. The concentrations of acetate, [Ac], and free (unbound) M2+, [M2+]f, are measured at different positions along the sample by CSI. Binding of M2+ to the polymer reduces [M2+]f and hinders the upward diffusion of M2+. A discrepancy is thus observed between [Ac] and [M2+]f from which the binding affinity of the polymer can be assessed. For systems which form insoluble complexes with M2+, such as sodium polyacrylate or carboxylate-functionalized nanocellulose (CNC), we can determine the concentration of M2+ at which the polymer will precipitate. We can also predict [M2+]f when a solution of polymer is mixed homogeneously with M2+ salt. We assess the binding properties of sodium polyacrylate, alginate, polystyrene sulfonate, CNC, polyethyleneimine, ethylenediamenetetraacetic acid, and maleate.
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影响因子：
11.2
作者：
SKJAKBRAEK, G;GRASDALEN, H;SMIDSROD, O
通讯作者：
SMIDSROD, O
影响因子：
4.4
作者：
MANNING, GS
通讯作者：
MANNING, GS
影响因子：
3.4
作者：
Afifi, NN
通讯作者：
Afifi, NN
DOI：
10.1080/09205063.2018.1433420
发表时间：
2018-01-01
影响因子：
3.6
作者：
Sarker, Md.;Izadifar, Mohammad;Chen, Xiongbiao
通讯作者：
Chen, Xiongbiao
影响因子：
10.7
作者：
Perumal, Anand Babu;Nambiar, Reshma B.;Anandharamakrishnan, C.
通讯作者：
Anandharamakrishnan, C.