Researcher(s)
- Natalie McClaine, Environmental Engineering, University of Delaware
Faculty Mentor(s)
- Yanfeng Yue, Chemistry, Delaware State University
Abstract
In this study, a phosphate ion-selective electrode (ISE) was fabricated using a membrane containing 5.6 mg tridodecylmethylammonium chloride (TDMACl), 13 mg ionophore, 32 mg polyvinyl chloride (PVC), and 64 mg o-nitrophenyl octyl ether (o-NPOE) dissolved in 1 mL tetrahydrofuran (THF). Europium, indium, cobalt, and copper complexes were evaluated as ionophores. A polished electrode was coated with 10 µL of carbon black and allowed to dry for 10 minutes before 100 µL of the membrane slurry was applied and dried overnight. The electrode was conditioned in 0.1 M phosphate solution for 24 hours and evaluated by open-circuit potential time measurements for 60 seconds in Na₃PO₄, Na₂HPO₄, and NaH₂PO₄ solutions ranging from 10⁻¹ to 10⁻⁶ M. Among the ionophores evaluated, the indium complex exhibited the highest phosphate sensitivity, with slopes of −20.8 and −28.8 mV/decade for Na₃PO₄ and Na₂HPO₄, respectively, and a response time below 30 seconds, demonstrating its potential for phosphate detection in water.