Determination and quantification of heavy metal ion by electrochemical method

Abstract

Today’s environment is polluted by heavy metal ions and toxic substances. The lead (Pb2+) is one of them which affect the environment by both natural and anthropogenic ways. Protection of the environment needs proper determination and quantification of these metal ions. Thus developing proper sensor with less cost is the focus of present research. Electrochemical sensor has attracted a great attention to determine these hazardous elements. In the present work sensor modified by blast furnace slag (BFS), provides a new opportunity for enhancing the electrocatalytic performance of fabricated sensor. The BFS was characterized by SEM, XRD, BET and particle size analyzer. Moreover different compositions of BFS were use to optimize the slag ratio. Furthermore the sensor modified material characterized by CV, Chronocoulometry, EIS and DPV. The electrochemical response towards Pb2+ on BFS modified sensor was explored by CV, EIS and DPV. Transfer coefficient (α) was calculated as 0.664 and rate constant (Ks) 1.08 s−1. The electrode was linear in the concentration range of 1–5 μM (R2 = 0.99). Experimental parameter like pulse height, step height, pH were also optimized. Detection and quantification limits were calculated as 0.015 μM and 0.053 μM respectively. This detection limit for Pb2+ is lower than the permissible limit provided by W.H.O. for drinking water. The electrode shows high sensitivity of 1068 μA/μM−1 cm-2 for Pb2+ ions with superior reproducibility and repeatability. The results suggested that blast furnace slag was a better material for heavy metal ion in aqueous solutions.