A novel silver(I)-selective PVC membrane sensor and its potentiometric applications

Authors: ÖMER IŞILDAK, NİHAL DELİGÖNÜL, OĞUZ ÖZBEK

Abstract: Silver(I)-selective sensors were prepared from a solid-state contact polyvinyl chloride (PVC) membrane. ($Z)$-2-(2-((3-(2-hydroxyphenyl)-5-(p-tolyl)-1$H$-pyrrol-2-yl)imino)-5-(p-tolyl)-2$H$-pyrrol-3-yl)phenol was synthesized as an ionophore molecule and embedded in the silver(I)-selective PVC membrane composition. The optimum membrane composition was determined as 2.5% ionophore, 61.7% bis-(2-ethylhexyl)sebacate, 1.0% potassium tetrakis (p-chlorophenyl) borate, and 34.8% PVC. The developed sensor exhibited a linear potential change $E$ = 67.42 (-log [Ag$^{+}$]) $+$ 1152.9 and $R^{2}$ = 0.9960) in the varying concentration range of 1.0 $\times $ 10$^{-1}$ to 1.0 $\times $ 10$^{-5}$ mol L$^{-1}$ silver ions. This sensor shows a detection limit of 7.3 $\times $ 10$^{-7}$ mol L$^{-1}$. The proposed sensor showed a good potential change with high sensitivity even in a wide range of pH values (2.0-11.0). The proposed sensor had a quick electrochemical response of less than 3 s with good selectivity and repeatability. The sensor was also successfully applied in the analysis of real water samples. In real water samples prepared by standard addition method, recoveries in the range of 82.30%-95.15% were obtained.

Keywords: Potentiometric sensor, PVC membrane, silver(I)-selective, silver determination

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