Iodide-selective screen-printed electrodes based on low-melting ionic solids and metallated phthalocyanine

Iodide‐selective electrodes were fabricated by modification of commercially available screen‐printed electrodes with low‐melting ionic solids (ionic liquids which are solidified at room temperature) and tetrakis(tert‐butyl)phthalocyaninatocobalt(III) iodide . The main potentiometric characteristics including the selectivity were determined. The best electrochemical characteristics were demonstrated by electrodes which surface has been modified by 1‐dodecyl‐3‐methylimidazolium hexafluorophosphate retaining the metallated phthalocyanine. The sensor works well over a concentration range from 1×10⁻⁵ to 1×10⁻¹ with nearly Nernstian response (−58.3±0.5 mV decade⁻¹); pH range is 2.0–11.5, response time is ca. 10 s. A good selectivity towards iodide over a number of anions was observed. The electrode was successfully used for the determination of iodide content in pharmaceuticals.