Amide and Acyl‐Hydrazine Functionalized Calix[4]arenes as Carriers for Hydrogen Phosphate Selective Electrodes

Abstract

Anion-selective solvent polymeric membrane based on hydrogen bond-forming, neutral ionophores with amide or acyl-hydrazine groups are described. The use of the two calix [4]arenes results in anion-selective electrodes with a selectivity for phosphate. The electrodes of the optimum characteristic have the composition of 1 wt% ionophore, 66 wt% o-NPOE, 33 wt% poly (vinyl chloride) (PVC) and TDMACl (15 or 30 mol% relative to the ionophore 1 and 2, respectively). The optimized membrane electrodes show Nernstian responses towards monohydrogen phosphate (À 29.1 and À 29.3 mV/decade) based on ionophore 1 and 2, respectively, in a wide concentration range (1.0 Â 10 À5 to 1.0 Â 10 À2 or 1.0 Â 10 À5 to 1.0 Â 10 À1 M). The selectivity coefficients are determined with the fixed interference method and the activity ratio method. The electrodes display an anti-Hofmeister series selectivity pattern and highly selective for HPO 4 2À over Cl . The lifetime of the electrodes is at least 1 month and their response time is found to be 25 s. The proposed sensors could be put to analytical use both by direct potentiometry as well as potentiometric titration.

Ion-Selective Electrodes in the Food Industry: Development Trends in the Potentiometric Determination of Ionic Pollutants

“…To date, compounds such as nicotianamide have been incorporated into PVC films with 2-nitrophenyl octyl ether plasticizer for the detection of phosphate [168]. Other molecules that can form such hydrogen bonds include thiourea [169] and Acyl-Hydrazine functionalized Calix [4]arenes [170]. However, the incorporation of these sensors in food analysis is still in its infancy, and additional work is required to develop sensing devices that can meet the current standards for practical applications.…”

Solid Contact Potentiometric Sensors Based on a New Class of Ionic Liquids on Thiacalixarene Platform

“…Calixarenes and their thia-analogs are macrocyclic compounds that offer unique opportunities of ionophore design due to the variety of functional groups in the substituents of the lower and upper rim of the macrocycle and pre-determined rigid spatial configuration of binding sites easily adapted to the guest molecule (ion) (Patra et al, 2012 ). The advantages of calixarene based receptors have been applied in the design of hydrogen phosphate receptors with good selectivity and sensitivity of the response (Yan et al, 2007 ). Calix[4]arene modifier was proposed for determination of inorganic anions including phosphates in snow water by capillary electrophoresis (Fernández-Gutiérrez et al, 2000 ).…”