Monitoring of Iron (III) Ions in Water Samples with a Fe3+-PVC Membrane Sensor

A new poly(vinyl chloride) (PVC) membrane electrode that is highly selective to Fe3+ ions was prepared by using 4, 4’-Dimethoxybenzil bisthiosemicarbazone (DBTS) as a suitable neutral carrier. Membrane incorporating 4, 4’- Dimethoxybenzil bisthiosemicarbazone (DBTS), as ionophore with composition DBTS:NaTPB:NB:PVC in the ratio 2:2:64:32 (w/w) exhibits the best result for potentiometric sensing of Fe3+ ions. The electrode exhibited a near- Nernstian response to Fe3+ in the concentration range of 1.0 × 10−6 to 1.0 × 10−2 M with a slope of 19.4 ± 0.5 mV per decade. The lower limit of detection was 3.6 × 10−7 M. This electrode showed high selectivity with respect to alkaline, alkaline earth, and heavy metal ions and could be used over a pH range of 1.8–5.0. It has been successfully used as for the determination of Fe3+ in water sample solutions (tap and mineral water samples).

کلیدواژه ها:

PVC Membrane ، Sensor ، Potentiometry