Investigation of Silver(I) Ion Sensing Property of Ruthenium(II) Thiosemicarbazone Complex Using Coated Graphite and Polymeric Membrane Electrodes

Abstract

AbstractA ruthenium(II) complex [Ru(PPh3)2(pytsc)2] {Hpytsc = pyridine‐2‐carbaldehydethiosemicarbazone, (C5H5N)C2(H)=N3‐N2(H)‐C1(=S)N1H} has been used as an ion carrier for the selective determination of silver(I) ions in solution. Silver(I) ion‐selective coated graphite based (CGE) and PVC polymeric membrane based (PME) electrodes exhibit Nernstian slope for silver(I) ions over a wide concentration range from 1.0 × 10−1 M to 5.0 × 10−6 M (with CGE) and 1.0 × 10−1 M to 2.0 × 10−5 M (with PME). The working pH range of these electrodes has been found to be from 1.2 to 7.2 for CGE and 2.2 to 6.5 for PME. The proposed CGE sensor exhibits better analytical features like sensitivity and selectivity towards different secondary ions in comparison to the corresponding PME with no interference from mercury(II) ions $({\rm log} K ^{Pot}_{AG{\rm ^{+}}, \textrm{ } Hg{\rm ^{2+}}}=-3.30)$. These electrodes also act as indicator electrodes in potentiometric titration and have been successfully used for the determination of silver content in solution of real samples (1 gm dissolved in 100 mL of dilute nitric acid) such as silver ornaments and thin silver foils. Silver content determined by the use of ion selective electrode was found to vary in the concentration range from 1.20 x 10−2 M to 7.45 x 10−2 M and results were found to be comparable with those obtained from the traditional volumetric method of analysis. It is the first report of a metal‐ligand complex used as an ion carrier in ion selective electrode, which is selective for a metal ion other than the one used in the complex.