Dipodal Tetraamide Derivatives of 1,10-Diaza-18-Crown-6 and Alkylmalonic Acids—Synthesis and Use as Ionophores in Ion Selective Membrane Electrodes

Abstract

Novel dipodal derivatives of an 18-membered diaza-crown ether with two diamide chains featuring methylmalonic or butylmalonic acid residues were obtained and tested as ionophores in ion-selective plasticized membrane electrodes. The objective of the study was to identify measurement conditions which ensure the most favorable performance for magnesium ion-selective electrodes. The relationship between the molar lipophilic anion salt-to-ionophore ratio and selectivity of electrodes was examined. The best result was obtained for the conventional electrode containing Mg2 ionophore. Calculated selectivity coefficients were as follows: logKMg/Ca = −2.77, logKMg/Na = −3.46 and logKMg.K = −2.24 (SSM, 1M).

Characterization of PVA-Enzyme Coated Indicator Electrodes GA coated again with PVC-KTpClPB-o-NPOE SEM-EDS, FTIR and XRD analysis

“…Ionophores (I) 1.10% (w/w), lipophilic salt (KTpClPB) 0.25% (w/w), plasticizer (o-NPOE) 65.65% (w/w), and PVC 33.00 % (w/w) dissolved in tetrahydrofuran (Lenar, 2020;Hasan, 2019); 0.05 wt% KTpClPB as membrane additive, and 1 wt% ionophore, 33 wt% PVC and 66 wt% plasticizer (o-NPOE) (Rizk, et al, 2009); 62.5 mg PVC, 130 mg o-NPOE, 1% by weight s prepared containing 62.5 mg PVC, 130 mg o-NPOE, 1% by weight ionophore and 80 to 140 mol% KTpClPB (relative to the ionophore). The membrane components were dissolved in 1.5 mL of THF (Pomećko, R., Luboch, E., and Jeszke, M., 2021).…”