Novel Potentiometric Strontium Membrane Sensor Based on Dibenzo-30-crown-10

Abstract

Potential response of strontium(II) ion selective electrode based on dibenzo-30-crown-10 (DBCE) as ion-carrier has been evaluated by varying the amount of ionophore, plasticizer, and anionic additive. The sensitivity, working range, response time, and metal ions interference have shown a significant dependence on the amount of ionophore, kind and amount of additive, and solvent mediator. The electrode prepared with 5% ionophore, 55% benzyl acetate, 10% oleic acid, and 30% PVC has shown a Nernstian slope of 29.20 mV per decade to activities of Sr²⁺ ions with a short response time of 10 s. The sensor has shown an appreciable selectivity for Sr²⁺ ions in the presence of alkali, alkaline earth, transition, and heavy metal ions and could be used in a pH range of 3.0–10.0. The wrap around complex of DBCE with Sr²⁺ contributed significantly to enhance the selectivity of the electrode. The electrode has shown an appreciable average lifetime of four months without any significant drift in the electrode potential. The sensor was applied as an indicator electrode in potentiometric titration of Sr²⁺ with EDTA and for direct determination of strontium in synthetic water samples.

Keywords:

• Strontium
• Sensor
• Dibenzo-30-crown-30
• PVC