Spectroscopic in Situ Imaging of Acid Coextraction Processes in Solvent Polymeric Ion-Selective Electrode and Optode Membranes
Abstract
Time-dependent processes induced by acidic solutions in solvent polymeric membranes with a H+-selective chromoionophore are studied in a spectropotentiometric setup. They are important for understanding the response time of anion-selective optodes and the response of H+-selective electrodes at low pH when anion interference is potential determining. The extent of anion - proton coextraction is characterized with extraction experiments on thin optical films (optodes) containing the same components and described by theory. Imaging experiments indicate rapid diffusion processes and unusual nonlinear steady-state concentration profiles that are explained by parallel extraction of undissociated acid into the membrane. Long-term potential drifts of the respective electrode are detected and related to the diffusion processes.
Publication Title
Analytical Chemistry
Recommended Citation
Lindner, E., Zwickl, T., Bakker, E., Lan, B., Tóth, K., & Pretsch, E. (1998). Spectroscopic in Situ Imaging of Acid Coextraction Processes in Solvent Polymeric Ion-Selective Electrode and Optode Membranes. Analytical Chemistry, 70 (6), 1176-1181. https://doi.org/10.1021/ac970952w
