Highly selective and sensitive copper(II) membrane coated graphite electrode based on a recently synthesized Schiff's base

A PVC membrane electrode based on bis-2-thiophenal propanediamine (TPDA) coated directly on graphite is described. The electrode exhibits a Nernstian response for Cu 2+ over a very wide concentration range (1.0 × 10 −1 to 6.0 × 10 −8 M) with a detection limit of 3.0 × 10 −8 M (2.56 ng ml −1 ). It has a fast response time and can be used for at least 2 months without any major deviation. The proposed sensor revealed very good selectivities for Cu 2+ over a wide variety of other metal ions and could be used in the pH range of 3.0–7.0. It was successfully used for direct determination of copper in black tea and as an indicator electrode in potentiometric titration of copper ion. © 2001 Elsevier Science B.V. All rights reserved.