Molybdate Anion Recognition through a Cationic Crowned Ionopore Based Electrochemical Sensor: Detection of an Environmental Pollutant

In the view of the complexities involved in the environmental cycling of hazardous metal species, attempts have been made to develop a poly (vinyl chloride) (PVC) based sensor for detection of MoO4 2ions using positively charged diaza crown ether (18-crown-6). The influence of membrane compositions on the potentiometric response of the electrodes have been found to substantially improve the performance characteristics of the membrane. Optimum performance was observed with the membrane having I-PVC-TBAB-DBP in the ratio 1:33:1:65 (w/w). The sensor shows a linear potential response for MoO4 2over a wide concentration range 2.5x10 -5 -1.0x10 -1 M with Nernstian compliance 31.2 mVdecade -1 of activity within pH range 5.8 to 10.9 and a fast response time of 30 s. The sensor has been found to work satisfactorily in partially non-aqueous media up to 15% (v/v) content of methanol, ethanol. It works over a period of 45 days with good reproducibility. The analytical usefulness of the proposed electrode has been evaluated by its application in the determination of molybdate ions in corrosion inhibitor samples.