Calcium ionophore IV – High Purity for ISE | Selectoprobe

References

Sokalski T, Ceresa A, Fibbioli M, et al.Lowering the Detection Limit of Solvent Polymeric Ion-Selective Membrane Electrodes. 2. Influence of Composition of Sample and Internal Electrolyte Solution . Anal. Chem, 1999, 71(6):1210-1214; DOI: 10.1021/ac9809332.

Abstract

The influence of the composition of the internal electrolyte solution on the response of Pb²⁺- and Ca²⁺-selective membrane electrodes is investigated. It is shown that the lower detection limit is improved by generating, in the membrane, ionic gradients that lead to a flux of primary ions toward the inner reference electrolyte solution. If the ion flux is too strong, it may cause analyte depletion at the membrane surface and, as a consequence, apparent super-Nernstian response. Such electrodes are not adequate to measure low analyte activities but can be used to determine unbiased selectivity factors. The results are interpreted in terms of a steady-state model, introduced in the companion paper, that describes the influence of concentration gradients generated by ion-exchange and coextraction processes on both sides of the membrane.

References

Wang, Y., Wang, X., Xu, H. et al. Self-plasticized Ca2+-selective electrode with polyaniline and copolymer of aniline and 2,5-dimethoxyaniline as solid contact layers . J Mater Sci ,2024,59:16129–16140 

Abstract

To address solubility, plasticizer leakage, and ionic carrier issues in PVC-based solid ion-selective electrodes, a novel plasticizer-free photocurable solid Ca²⁺-selective electrode (GC/PANI/CPANI/Ca²⁺(PBA)-ISE) was developed using a novel electrode structure. A new Ca²⁺-sensitive membrane based on poly(butyl acrylate) (PBA) was synthesized by ultraviolet polymerization, with conductive polyaniline (PANI) as the solid contact layer and a copolymer of aniline and 2,5-dimethoxyaniline (CPANI) as the coating. All potential electrochemical tests were carried out on the prepared Ca²⁺-selective electrode. The response slope of the electrode was 28.33 mV decade⁻¹, the detection limit was 6.9 × 10⁻⁶ M, the stable linear range was 1 × 10⁻⁶ to 1 × 10⁻² M, and it had a good Nernst response. The chronopotentiometric analysis and water layer tests showed that the potential drift of GC/PANI/CPANI/Ca²⁺(PBA)-ISE was as low as 0.0125 mV s⁻¹ and 1.247 mV h⁻¹. In addition, the interference tests of environmental factors were carried out. When the electrode was in different interference light and gas environments, the potential changes of 1.6 × 10⁻⁴ mV s⁻¹ and 1.2 × 10⁻³ mV s⁻¹ were observed. Compared with previous reports and commercial electrodes, the prepared GC/PANI/CPANI/Ca²⁺(PBA)-ISE showed good electrochemical performance, and the recovery rate in Ca²⁺ test solutions was higher (97.2–99.9%). This study provided theoretical insights to address solubility, plasticizer leakage, and ion carrier leakage issues in solid-state contact ion-selective electrodes. At the same time, this study provided a new structure and preparation method for the preparation of all-solid-state Ca²⁺-selective electrode.

 

Calcium ionophore IV | C52H100N2O3 | CID 601910 - PubChem (nih.gov)