Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

Abstract

The newly synthesized copper(II) complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride) (PVC) based membrane electrode selective to Cu(II) ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM). The electrode can also be used in partially non-aqueous media having up to 25% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

Keywords

• Poly(vinyl chloride)
• Nernstian slope
• Copper(II)-selective electrode
• Schiff base complex
• Potentiometry