Novel solid-state mercury(II)-selective electrode based on symmetrical sulfur-containing carrier

A new mercury solid-state ion-selective electrode has been prepared by directly coating the surface of a platinum disk electrode with tetrahydrofuran (THF) solution containing poly(vinyl chloride) (PVC), 1,2-bis(quinolin-8-ylsulfanylmethyl)benzene (BQSB), dioctyl phthalate (DOP) and potassium tetrakis(p-chlorophenyl)borate (KTpClPB). The electrode exhibits a Nerstian response in the range of 1.0 × 10− 7-1.0 × 10− 2 M with a detection limit and slope of 8.0 × 10− 8 M and 29.7 ± 0.3 mV/decade respectively. The response time to achieve a 95% steady potential for Hg2 + concentration ranging from 1 × 10− 5 to 1 × 10− 2 M is ~ 15 s, and the electrode is suitable for use within the pH range of 1.7-4.0. The proposed electrode revealed fairly good discrimination ability towards Hg+ 2 in comparison to some alkali, alkaline earth, transition and heavy metal ions. Applications of this electrode for the determination of mercury in environmental waters, and as an indicator electrode for potentiometric titration of Hg+ 2 ions with iodide, were reported. It could be applied for the determination of mercury in environmental waters.