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 Cu2+ over a very wide concentration range (1.0 x 10(-1) to 6.0 x 10(-8) M) with a detection limit of 3.0 x 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 Cu2+ 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. (C) 2001 Elsevier Science B.V All rights reserved.