1. A Selective Membrane Electrode for Thiocyanate Ion Based on a Bis-taurine-salicylic Binuclear Copper(II) Complex as Ionophore
- Author
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Chen Chun-Hua, Xu Lan, Yuan Ruo, Dai Jian-yuan, Chai Yaqin, and Wang Fu-Chang
- Subjects
chemistry.chemical_compound ,Thiocyanate ,chemistry ,Electrode ,Inorganic chemistry ,Potentiometric titration ,Ionophore ,chemistry.chemical_element ,Infrared spectroscopy ,General Chemistry ,Selectivity ,Copper ,Ion selective electrode - Abstract
The response characteristics of a new potentiometric membrane electrode with unique selectivity towards thiocyanate ion were reported. The electrode was prepared by incorporating bis-taurine-salicylic binuclear copper(II) complex into a plasticized PVC-membrane. The resulting electrode exhibits anti-Hofmeister selectivity sequence: SCN−>I−>ClO4−>Sal−>NO3−>NO2−>Br−>Cl−>SO3−>SO42− and a near-Nernstian potential linear range for thiocyanate from 1.0A×10−1 to 1.0A×10−6 mol·L-1 with a detection limit of 8.0A×10−7 mol·L−1 and a slope of −56.5 mV/pc in phosphate buffer solution of pH 5.0 at 20°C. The UV/Vis spectra, IR spectroscopy and AC impedance studies showed that the excellent selectivity to thiocyanate was related to the unique interaction between the central metal and the analyte and a steric effect associated with the structure of the carrier. The electrode was successfully applied to the determination of thiocyanate in waste water and human urine samples.
- Published
- 2005