Triiodide PVC membrane electrodes based on charge-transfer complexes.
Three new electrodes were prepared by incorporating two different charge-transfer complexes and amino crown ether into plasticized PVC membranes. The electrodes showed Nernstian response to triiodide ion over the activity range from 1.0 x 10(-5) to 1.0 x 10(-1) mol x L(-1) with detection limits at approximately 1.0 x 10(-6) mol x L(-1). The resulting electrodes have fast response times (20-30 s) and good stabilities (4 months) and can be used over a wide pH range of 2.5-9.0. The proposed electrodes exhibit anti-Hofmeister behavior with excellent selectivity toward triiodide ion against a wide range of common interferences. Comparative study suggests that amino (aza) crown ether alone or in the form of a charge-transfer complex with iodine, as an ionophore in a PVC liquid membrane, is sensitive to triiodide ion. The electrodes were used as indicator electrodes in potentiometric titration of triiodide ion against thiosulfate ion.
Sadeghi
Susan
S
Department of Chemistry, University of Birjand, Khorasan, Iran. Chemsad2001@Yahoo.Com
Dashti
Gholam Reza
GR
D004563:Electrochemistry; D004566:Electrodes; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D011143:Polyvinyl Chloride / Q000737:chemistry*; D011199:Potentiometry
D007202:Indicators and Reagents; D008567:Membranes, Artificial; D011143:Polyvinyl Chloride