Zinc(II)-selective PVC membrane potentiometric sensor for analysis of Zn2+ in drug sample and different environmental samples

Abstract

ABSTRACT In this study, a novel potentiometric sensor that is highly selective to Zn2+ ions is described. A highly selective and sensitive all-solid-state poly(vinyl chloride) membrane Zn2+ sensor, using 7,16-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane as an ionophore, has been prepared. The best performance was obtained with the sensor having a membrane composition of 4.0% ionophore, 33.0% poly(vinyl chloride), 62.0% Bis(2-ethylhexyl) sebacate (BEHS) and 1.0% potassium tetrakis (p-chlorophenyl) borate (KTpClPB). The sensor exhibits a Nernstian slope of 28.0 ± 2.0 mV/decade in a wide linear concentration range of 1.0 × 10−5 to 1.0 × 10−1 M and detection limit of this sensor is 1.17 × 10−6 M. The developed potentiometric sensor showed a relatively fast response time of 5 s, good reproducibility and stability. The proposed sensor revealed good selectivity over a wide variety of other cations. The working pH range of this sensor is 4.0–11.0. The developed zinc(II)-selective sensor was successfully applied to the direct zinc determination in different water samples and drug sample. The potentiometric results for the drug sample was compared with inductively coupled plasma spectrometry. The proposed zinc(II)-selective electrode can be successfully employed as an indicator electrode in potentiometric titration with EDTA.