Cd (II) Ion-Selective Electrode Based on 2 –Acetylthiophene Semicarbazone in Polymeric Membrane

Abstract

A new polyvinylchloride membrane sensor for Cd 2+ ions has been prepared using 2-acetylthiophene Semicarbazone (ATS) ligand as an electroactive ionophore and dibutylphthalate (DBP) as a plasticizing agent. The best performance was recorded with a membrane composition of PVC: DBP: Ionophore: NaTPB as 31: 64: 3.2: 1.8 (w/w %). The sensor exhibits a Nernstian response for Cd 2+ ions over a wide concentration range (1.0×10-5 to 1.0×10-1 M) with a slope of 29.4±0.2 mV decade-1. It has a fast response time of ˂10 s and can be used for at least 5 weeks without any divergence in potential. The electrode can be used in the pH range from 3.4 to 7.6. The proposed sensor revealed relatively good selectivity and high sensitivity for Cd 2+ ions in presence of a number of mono, di and trivalent interfering cations within the working range of the electrode. The electrode was successfully applied for the direct determination of Cd 2+ in solution and, as an indicator electrode, in potentiometric titration of cadmium ions using ethylenediamine tetraacetic acid (EDTA) as titrant.

Depth profiling X-ray photoelectron spectroscopy and atomic force microscopy of Cd(ii)- and Pb(ii)-selective electrodes based on nano metal sulfides

“…This indicates leaching of the CdS nanoparticles from the membrane to the bathing solution as a result of the soaking process. These results accord with those of a previous study 14 on a hydralazinium-selective electrode. It is worth noting that for both membranes, the content of Cd at the surface was higher than in-depth, which is attributed to penetration of Cd( ii ) ions from the bathing solution into the gel layer of the membrane surface during the conditioning and working time.…”

“…In general, the present electrodes showed comparable, and in some cases better performance characteristics over the recently published corresponding electrodes. For example, 3-acetylsemicarbazone ligand has been used 14 as ionophore in Cd( ii )-selective electrode based on PVC membrane plasticized with dioctylphthalate. The electrode showed Nernstian response over the concentration range 1.0 × 10 −5 to 1.0 × 10 −1 .…”

Selective and sensitive determination of Cd(II) ions in various samples using a novel modified carbon paste electrode

“…1.0 × 10 − 6 -1.0 × 10 −1 29.1 ± 1 3.5-7.9 13 35 (Rezaei et al 2008b) 4 N,N′-(4 methyl 1,2 phenylene) diquinoline-2 carboxamide 1.0 × 10 −6 -1.0 × 10 −1 29.9 ± 0.5 4-9 8 3-8 (Ensafi et al 2009) 5 4-Hydroxy salophen 1.0 × 10 −6 -1.0 × 10 −1 30.1 ± 1 2.8-8.1 8 20 (Mohan et al 2016) 6 2-Acetylthiophene Semicarbazone 1.0 × 10 −5 -1.0 × 10 −1 29.4 ± 0. .5 × 10 − 7 -1.0 × 10 −1 4.0 × 10 − 7 -2.0 × 10 −1…”

A rapid cadmium determination based on ion selective membrane potentiometric sensor by bis (salicylaldehydo)ethylenediimine as carrier

“…Many ionophores are lipid-soluble entities that transport ions across the cell membrane. They are suitable ionophore to form effective ionselective electrodes, because of affinity toward metal ions [9,10]. The Schiff bases are ligands with mixed O,N-donor atoms which bonds to some transition metal ions, such as Mn(II), Fe(III), Cu(II), Pb(II), Cd(II).…”