Uultra-trace determination of cadmium (II) in aqueous environmental samples by a new ion selective electrode based on nefazodone and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid

Cadmium is a potential environmental contaminant that causes adverse effects on the environment and the health of living organisms. Therefore, designing a simple and economic technique for its determination is very important. In this respect, a potentiometric sensor based on nefazodone as the ionophore and [BMIM]PF6 as the ionic additive were developed for the determination of ultra-trace amounts of cadmium (II),.

In this study, a new membrane ion selective electrode was constructed with a composition entailed of 10% nefazodone, 2% [BMIM]PF6, 30% PVC and 58% dioctyl phthalate (DOP).The created potential discrepancy between the membrane and reference electrodes was used as a signal which demonstrates a direct relationship with the logarithmic concentration of cadmium (II) for  its determination.

The constructed sensor showed an appropriate Nernstian slope (30.5 mV. Decade-1) in a wide concentration range (1×10-9 - 8×10-2 M) with the detection limit of 6×10-9 M. The electrode potential was pH-independent in the range of 3.5-8.0. The response time and lifetime of the electrode obtained 5 s and 15 weeks, respectively.

The constructed sensor independent of sample preparation was employed successively for the measurement of low concentrations of cadmium (II) in the environmental samples .Moreover,  the obtained findings were in a good agreement with the results of flame atomic absorption spectroscopy. Therefore, the designed electrode established pinpoint accuracy and it can be used for the determination of cadmium (II) in aqueous samples.