Simultaneous Electrochemical Detection of Pb and Cd by Carbon Paste Electrodes Modified by Activated Clay
Niraka Blaise, Valery Hambate Gomdje, Raja Maallah, Mohamed Oubaouz, Bakary Tigana Djonse Justin, Edwin Andrew Ofudje, Abdelilah Chtaini
Abstract
Calcinated and acidified clay modified carbon graphite electrode was deployed in the simultaneous evaluation of traces of Pb 2+ and Cd 2+ in solution. After 5 minutes of accumulation in the circuit, the sensitivity of the electrode was evaluated in a solution of Na 2 SO 4 (0.1 M) by square wave voltammetry on the one hand with Pb (II) and on the other hand with Cd (II). Several experimental conditions such as the composition of the carbon clay paste, the effect of preconcentration time, the sweeping speed, concentration effect, media pH, and interference ionic response to the electrochemical response of the working electrode were examined. It was observed that, after 5 minutes of preconcentration, detection limits of 0.15513 μ mol·L −1 and 0.24227 μ mol·L −1 were obtained for Pb 2+ and Cd 2+ in the electrolyte solution and 0.08438 μ mol·L −1 and 0.46522 μ mol·L −1 , respectively, when tap water was used. The detection was effective by square wave voltammetry with a more intense current density with respect to lead.