A Novel Modified Carbon Paste Electrode for Potentiometric Determination of Mercury(II) Ion

Abstract

AbstractA new modified carbon paste electrode (CPE) based on a recently synthesized ligand of Ethyl‐2‐(benzoylamino)‐3‐(2‐hydroxy‐4‐methoxyphenyl)‐2‐propenoate (EBHMP) as a suitable carrier for Hg2+ ion was described. The electrode exhibit a super Nernstian slope of 48.5±1.0 mV per decade for Hg2+ ion over a wide concentration range from 3.0×10−7–3.1×10−2 M. The lower detection limits are 1.0×10−7 M Hg2+. The electrode has a fast response time (ca. 5 s), a satisfactory reproducibility and relatively long life time. The proposed sensor shows a fairly good selectivity toward Hg2+ ion in comparison to other common cations. The potentiometric responses are independent of the pH of the test solution in the pH range 1.0–4.0. The proposed electrode was used as an indicator electrode in potentiometric titration of mercuric ion with standard solution of EDTA. The direct determination of mercury in spiked wastewater and an amalgam sample gave results that compare favorably with those obtained by the cold vapor atomic absorption spectrometric method.