Determination of Lead Ion by a Modified Carbon Paste Electrode Based on SiO₂ Nanoparticles, Ionic Liquid and Ionophore (N, N , N -Tricyclo Hexil Phosphoric Triamid) by Potentiometric Method

The aim of this study was the determination of lead ion concentration by Carbon Paste Ion Selective electrode. The electrode response characteristics have been investigated. Material and methods: The Carbon Paste Electrode (CPE) contains Graphite powder, Nanoparticles, Ionophore and Ionic liquid. The potential measurements were carried out with a Potentiometer. The selectivity of the electrode towards different cationic species was evaluated by Separate Solution Method (SSM). The results: Among the different compositions studied, the carbon paste incorporating 60% graphite powder, 29% Ionic Liquid, 5%Ionophore and 6%Nanoparticles exhibit the best response characteristics. The electrode exhibits a linear response to Pb (II) over a concentration range (1.0×10−8 – 1.0×10−1) with a Nernstian slope of 30.03 MV per decade. It has a short response time (about 5 s). The detection limit of this electrode was 8.0×10−6 M. The potential remains constant in the range of PH=7-11. Conclusion: The suggested electrode was successfully used as an indicator for potentiometric determination of Pb (II) in water samples. It was characterized by good analytical parameters: low detection limit, high sensitivity, wide measuring range, wide pH range. All selected cations would not affect the selectivity of the present Lead electrode.