Voltammetric Characterization of Cu(II) Complexation in Real-Time

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• 作者：Thushani Siriwardhane ; Audrey Sulkanen ; Pavithra Pathirathna ; Annette Tremonti ; Shawn P. McElmurry ; Parastoo Hashemi
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：August 2, 2016
• 年：2016
• 卷：88
• 期：15
• 页码：7603-7608
• 全文大小：303K
• 年卷期：0
• ISSN：1520-6882

文摘

Aqueous metal behavior is strongly regulated by speciation, which in turn is highly dependent on complexation. Trace metal complexation is difficult to characterize in dynamically changing systems due to a lack of analytical methods that can rapidly report free-metal concentrations. In this paper, we perform proof-of-principle experiments that demonstrate the utility of fast-scan cyclic voltammetry (FSCV) for providing speciation information in real-time by characterizing dynamic Cu(II) binding. We study Cu(II) FSCV responses in 3-(N-morpholino)propanesulfonic acid (MOPS) buffer and characterize the hydrodynamic aspects of our experimental setup (continuously stirred tank reactor). We observe Cu(II) complexation in real-time using five ligands with differing formation constants of Cu(II) complexation. Finally, we utilize geochemical models to fit our real-time experimental Cu(II)-binding curves. Our proof-of-principle experiments show that FSCV is a powerful tool for studying real-time Cu(II) complexation, which is essential speciation information for better interpretation of Cu(II) behavior in dynamically changing systems, such as those encountered in biology or the environment.