Highly Salicylate‐Selective Membrane Electrode Based on N,N′‐bis‐(Furaldehyde)‐Glycine Copper(II) Complex as Neutral Carrier

Abstract

A novel salicylate‐selective poly(vinyl chloride) (PVC) membrane electrode based on N,N′‐bis‐(furaldehyde)‐glycine copper(II) complex [Cu(II)‐BFAG] as neutral carrier is reported, which exhibits anti‐Hofmeister selectivity sequence: Sal⁻ > ClO₄ ⁻ > SCN⁻ > I⁻ > NO₃ ⁻ > NO₂ ⁻ > Br⁻ > Cl⁻ > SO₃ ²⁻ > SO₄ ²⁻ and a near‐Nernstian potential linear range for salicylate from 1.0 × 10⁻¹ to 4.0 × 10⁻⁶ mol/L, with a detection limit of 8.0 × 10⁻⁷ mol/L and a slope of −56.8 mV/pSal⁻ in pH 5.0 of phosphate buffer solution at 25°C. The response mechanism is discussed in view of the A.C. impedance and the ultraviolet (UV) spectroscopy technique. The effects of the electrode membrane compositions and the experimental conditions were studied. The electrode based on copper(II) compound was applied to the determination of salicylate ion in drug pharmaceutical preparations with satisfactory results.

The support of this work by the National Natural Science Foundation of China (29705001), the Chinese Education Ministry Foundation for excellent young teachers (2002‐40), and the Natural Science Foundation of Chongqing city (2002‐7477), China, are gratefully acknowledged.

Keywords:

• N,N′‐bis‐(furaldehyde)‐glycine copper(II)
• neutral carrier
• salicylate
• ion‐selective electrode

Notes

The support of this work by the National Natural Science Foundation of China (29705001), the Chinese Education Ministry Foundation for excellent young teachers (2002‐40), and the Natural Science Foundation of Chongqing city (2002‐7477), China, are gratefully acknowledged.