1-Hexyl-3-methylimidazolium hexafluorophosphate as new component of polymeric membrane of lead ion-selective electrode

abstract

The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate is used as a new lipophilic ionic additive in the polymeric membrane of a solid contact type lead ion-selective electrode. The membrane is deposited on an internal glassy carbon electrode with poly(3-octyl)thiophene as an intermediate layer. The sensor exhibits good analytical parameters: low detection limit of 3.5 × 10⁻⁹ mol L⁻¹, Nernstian response slope of 29.8 mV/decade, a wide concentration range of 1 × 10⁻⁸−1 × 10⁻¹ mol L⁻¹, short response time of 7 s, and relatively long lifetime of 100 days. The proposed sensor has a working pH range of 4.0–6.9 and excellent selectivity for Pb(II) ions over a wide variety of other metal ions. The efficiency of the proposed sensor was demonstrated by its application for direct determination of Pb²⁺ ions in real water samples.

Keywords:

• Ionic liquid
• Ion-selective electrode
• Solid contact
• Lead determination

Notes

Presented at the International Conference on Desalination for the Environment, Clean Water and Energy, European Desalination Society, 23–26 April, 2012, Barcelona, Spain