Sensing of Lead and Copper Metal Ions by Substituted N-Methyl Piperazine Compound on Glassy Carbon Electrode

Use of a 2,4 bis (4-methyl piperaz-yl-methyl) 1-4' hydroquninoe (L) modified glassy carbon electrode (LMGCE) enhance the oxidation and reduction current of Pb(NO₃)₂ and CuSO₄ during cyclic voltammetry compared to bare glassy carbon electrode. Peak potential was not significantly changed as compared with unmodified one. The sensitivity under conditions of cyclic voltammetry is significantly dependent on the scan rate. The transfer co-efficient values were calculated to be 0.013 and 0.078 for Pb²⁺ and Cu²⁺ ions respectively. The detection limit of this modified electrode was found to be 1 x 10^-4M for Pb²⁺ and Cu²⁺ ions at glassy carbon electrode. The reduction and oxidation current of Pb(NO₃)₂ and CuSO₄ was higher at first cycle and became stable with minor decreases after second cycle. It is therefore evident that the LMGCE posses some degree of stability. The diffusion co-efficient values for Pb²⁺ and Cu²⁺ ions on LMGCE were calculated by the chronoamperometry which is in the value of 8.3 x 10^-7cm²/s and 3.5 x 10^-6 cm²/s respectively. The reduction of Pb²⁺ and Cu²⁺ ions on L MGCE was studied by chronocoulometry which is supported to the cyclic voltammetry results. The tolerance limit of the lead and copper ion is 1 x 10^-3M which is detected from the interference study of cadmium and mercury ions.