New Pb(II)-selective membrane electrode based on a new Schiff base complex

Abstract

Schiff base complex [Co(L) 2 ](ClO 4 )·(C 3 H 6 O)·(H 2 O) ( 1 ) was synthesized and structurally determined [L = 2-((E)-(3-aminopyridin-4-ylimino)methyl)-phenol and C 3 H 6 O = acetone]. With 1 as the ionophore a new Pb(II)-selective membrane electrode was exploited. The electrode exhibits Nernstian response to Pb(II) over a wide concentration range (1.0 × 10 − 5 to 1.0 × 10 − 2 M), with a slope of 23.9 mV/dec, a fast response time ( t 95% = 10 s), and a lower detection limit of 4.6 × 10 − 6 M. It has acceptable selectivity for Pb(II) over a wide variety of other metal ions in a wide pH range of 4–13, showing practical detection for Pb(II). A new Pb(II)-selective membrane electrode with mononuclear Schiff base complex [Co(L) 2 ](ClO 4 )·(C 3 H 6 O)·(H 2 O) ( 1 ) [L = 2-((E)-(3-aminopyridin-4-ylimino)methyl)-phenol and C 3 H 6 O = acetone] as the ionophore was synthesized and investigated. ► Ionophore of Schiff base complex. ► Crystal structure of mononuclear Co(II) complex. ► Pb(II)-selective membrane electrode. ► Potentiometric sensor.