Development of polyvinyl chloride (PVC)-based highly efficient potentiometric sensors containing two benzene-centered tripodal diglycolamides as ionophores

Abstract

Two potentiometric sensors were developed containing tailor made multiple diglycolamide-containing ionophores based on the planar benzene scaffold, viz. LI and LII, embedded in a polyvinyl chloride (PVC) membrane. The membrane composition was optimized for best analytical performance for the detection of Eu(III) in acidic solutions. In order to improve the conductivity and homogenization of the components inside the membrane, 2-nitrophenyloctyl ether (NPOE) was used as the plasticizer. FTIR measurements were done to characterize the membranes for the presence of free binding groups suitable for the interaction with and uptake of Eu(III) ion. The analytical performance of the membranes was examined in a wide range of Eu(III) concentrations in nitric acid solutions. The linear dynamic range of both the LI- as well as the LII-based membranes was determined as 8.8 × 10−7 to 2.6 × 10−3 M with a detection limit of Eu(III) as 8.6 × 10−7 M and 8.4 × 10−7 M, respectively. The sensor was tolerant of the commonly occurring interfering agents. The developed potentiometric sensors were applied for the determination of Eu(III) in real water samples.