A Strontium (II) Selective PVC Membrane Electrode Based onKryptofix 5 as an Ionophore

A potentiometric strontium-selective electrode based on kryptofix5 in PVC matrix for measurement of strontium ion is reported. The electrode was prepared by coating the surface of a graphite by a membrane containing nitrobenzene (NB), kryptofix5 and NaTPB in poly vinyl chloride (PVC) in tetrahydrofuran (THF). The membrane composition consisting of kryptofix5 , PVC, NB, NaTPB, the thickness of coated membrane, effect of pH and possible interfering cations were investigated and optimized electrode were evaluated. The electrode exhibits significantly enhanced response toward strontium ions over the concentration range1 × 10-6 to 1 × 10-1 M with slope of 29.2±0.3 mV/decade change of concentration and a detection limit of 4.54×10-7 M. Fast and stable response, good reproducibility, long-term stability is demonstrated. The electrode has a response time of 5 s and can be used for at least 2 weeks without any considerable divergence in their potential response. The proposed electrode shows fairly good discrimination of strontium from several cations. The practical utility of the electrode has been demonstrated by using it successfully as an indicator electrode in the potentiometric titration of Sr2+ with EDTA In addition, this electrode was successfully used for determination of strontium in real samples.

کلیدواژه ها:

Strontium ion-selective electrode ، Kryptofix 5 ، Potentiometry ، Graphite electrode