IPREM, UMR 5254, Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, 64053 Pau, France.
Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Unité Mixte de Recherche (UMR), Centre National de la Recherche Scientifique (CNRS), Université de Lorraine, UMR 7360, 54500 Vandœuvre-lès-Nancy, France.
Molecules. 2023 Jan 14;28(2):846. doi: 10.3390/molecules28020846.
The Donnan membrane technique (DMT), in which a synthetic or natural solution (the "donor") is separated from a ligand-free solution (the "acceptor") by a cation-exchange membrane, is a recognized technique for measuring the concentration of a free metal ion in situ, with coupling to electrochemical detection allowing for the quantification of the free metal ion directly on site. However, the use of the DMT requires waiting for the free metal ion equilibrium between the donor and the acceptor solution. In this paper, we investigated the possibility of using the kinetic information and showed that non-equilibrium experimental calibrations of Cd and Pb with the ISIDORE probe could be used to measure free metal concentrations under conditions of membrane-controlled diffusion transport. The application of this dynamic approach made it possible to successfully determine the concentration of free Cd in synthetic and natural river samples. Furthermore, it was found that the determination of free Cd from the slope was not affected by the Ca concentration ratio between the acceptor and donor solution, as opposed to the traditional approach based on Donnan equilibrium. This ISIDORE probe appears to be a promising tool for determining free metal ions in natural samples.
唐南膜技术（DMT）是一种将合成或天然溶液（“供体”）与无配体溶液（“受体”）通过阳离子交换膜隔开的技术，它是一种原位测量游离金属离子浓度的公认技术，与电化学检测相结合可以直接在现场定量游离金属离子。然而，DMT 的使用需要等待供体和受体溶液之间游离金属离子的平衡。在本文中，我们研究了利用动力学信息的可能性，并表明可以使用 ISIDORE 探针对 Cd 和 Pb 进行非平衡实验校准，以在膜控扩散传输条件下测量游离金属浓度。这种动态方法的应用使得成功测定合成和天然河流样品中游离 Cd 的浓度成为可能。此外，与基于唐南平衡的传统方法相反，发现从斜率确定游离 Cd 的浓度不受受体和供体溶液之间 Ca 浓度比的影响。ISIDORE 探针似乎是一种很有前途的测定天然样品中游离金属离子的工具。
