Highly Selective Perchlorate Membrane Electrode Based on Cobalt(III) Schiff Base as a Neutral Carrier

A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(III)‐Schiff base [Co(5‐NO₂‐ Salen)(PBu₃)]ClO₄·H₂O (where 5‐NO₂‐SalenH?bis(5‐nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate‐selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10^?6 to 5.0×10^?1 mol·L^?1 with a slope of (59.4±0.9) mV per decade of perchlorate concentration with a low detection limit of 5.0×10^?7 mol·L^?1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (<5 s) and a wide pH independent range (3.0–12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.