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

Schiff base complex [Co(L)2](ClO4)·(C3H6O)·(H2O) (1) was synthesized and structurally determined [L = 2-((E)-(3-aminopyridin-4-ylimino)methyl)-phenol and C3H6O = 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 (t95% = 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).

Graphical abstractA new Pb(II)-selective membrane electrode with mononuclear Schiff base complex [Co(L)2](ClO4)·(C3H6O)·(H2O) (1) [L = 2-((E)-(3-aminopyridin-4-ylimino)methyl)-phenol and C3H6O = acetone] as the ionophore was synthesized and investigated.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ionophore of Schiff base complex. ► Crystal structure of mononuclear Co(II) complex. ► Pb(II)-selective membrane electrode. ► Potentiometric sensor.