A Schiff Base Complex of Zn(II) as a Neutral Carrier for Highly Selective PVC Membrane Sensors for the Sulfate Ion

Abstract

Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets.

Iodide-selective membrane electrode based on salophen complex of cobalt (III)

“…In Table 2, the analytical performance and selectivity coefficients for diverse anions of the proposed electrode are compared with the corresponding values previously reported for iodide ion-selective membrane electrodes. 20,22,[25][26][27]33,34,44,45 The data given in Table 2 indicate that, the selectivity coefficients, linear range, response time, pH range and slope of calibration graphs somewhat similar, in some case, or even superior, in most cases, to the sensors prepared previously. Therefore, on the basis of these data, we may conclude that the membrane sensor, proposed in this work is among the most selective and sensitive electrodes reported thus far for iodide ion.…”

“…Recently, there have been a few reports on ionophores that when introduced into solvent polymeric membranes bring about iodide selectivity very divergent from the Hofmeister series. 24,[26][27][28][32][33][34] To obtain a clue about the interaction mechanism of CoSPPClO 4 with iodide, the UV-Vis. spectra of 1.0×10 -4 mol L -1 CoSPPClO 4 in CH 3 CN were obtained with and without the presence of 1.0×10 -4 mol L -1 iodide and the results are shown in Figure 2.…”

“…It has been show that the anion selectivity behavior of membrane electrodes based on different transition metal complexes is influenced by both the properties of the central metal ions and the structure of organic ligands. 7,20,[24][25][26][27] The salophen (N,N'-disalicylidene-1,2-phenylendiamine dianion) as a polydentate ligand are well know to form very stable complexes with transition metal ions. 28 ions.…”

Convenient and mild synthesis and characterisation of some new Schiff bases

“…They are used as the catalyst in reactions. These compounds also find many important catalytic applications, ranging from asymmetric epoxidation [16], Lewis acid assisted organic transformations [17], solid phase extraction of metal ions [18] to various types of polymerization [19][20][21][22] as well as their application for the preparation of ion selective electrodes [23][24][25][26][27]. Recently, Ayla Balaban Gunduzalp and co-worker have been prepared and characterized complexes of tetra dentate Schiff base ligands [28].…”

Aluminum(III)‐selective PVC Membrane Electrode Based on Salicylaldehyde Salicyloyl Hydrazone

“…[18][19][20][21][22][23] The Schiff bases are known to be able to form stable complexes with metals and act as ion carriers in the poly(vinyl chloride) (PVC) membrane. [24][25][26] In this work, we investigated a highly selective PVC membrane electrode for Al 3+ based on a Schiff base of salicylaldehyde salicyloyl hydrazone (SSH). The sensor displays a Nernstian response for Al 3+ over a wide linear range with a low detection limit.…”