A polyvinylchloride-based cadmium ion-selective electrode using [Mo _2(OAc)_2(H_2-calix[4]arene)] as an electroactive material

摘要

A highly electroactive material Mo_2[(OAc)_2(H _2-calix[4]arene)] is used as a neutral carrier for Cd~(2+) ions in this paper. The membrane is fabricated by using ionophore [Mo _2(OAc)_2 (H_2-calix[4]arene)]:poly(vinyl chloride) (PVC): dibutylphthalate(DBP):sodium tetraphenyl borate (NaTPB) in the ratio of 40:300:470:5 respectively and tetrahydrofuran (THF) used as a solvent. The membrane electrode performed in the concentration range of 9.9 × 10~(-8)- 1.0 × 1021M (2.34 × 10~(-5)-23.64 mg/mL) having the Nernstian slope of 30.0 ^ 1.0mV and the best detection limit was observed at 9.8 × 10~(-8)M (2.31 × 10~(-5) mg/mL). The proposed membrane electrode has the response time of 12 s and a useful working pH range of 1.0-7.0, and used over a period of 10 months and work satisfactorily in the test solution having 30% (v/v) non-aqueous content. Electrode sensor has distinguishable ability for Cd2+ ion with regard to several alkali, alkaline earth, transition and heavy metal ions. It was used in direct potentiometry as an indicator electrode, in the potentiometric titration of 10~(-3)M Cd~(2+) solution against 10~(-2)M of ethylenediaminetetraacetic acid (EDTA).