Iron (III) selective measurement based on kryptofix 5 as a carrier

In this research project, a highly selective iron coated graphite electrode was prepared by kryptofix 5 as a macromolecule ionophore into plasticized polyvinylchloride (PVC) membrane. The best response characteristic was observed using the membrane composition of nitrobenzen (NB) = 65.0 mg, PVC = 30.0 mg, sodium tetraphenylborate (NaTPB) = 2.0 mg and kryptofix 5 = 3.0 mg. The sensor exhibits a Nernstian slope (19.5±0.5 mV/decade) in a linear concentration range of 1.0×10-5 to 1.0×10-2 M. The detection limit of the electrode is 6.3×10-6M. The electrode has a fast response time of 10 s, with a satisfactory reproducibility and relatively long life time of 5 weeks without significant drift in potential. The electrode operates in the wide pH range of 4-11.

Keywords:

Iron (III) cation , Ion selective electrode , Potentiometry