50
Views
3
CrossRef citations to date
0
Altmetric
CHEMICAL AND BIO-SENSORS

Coated Graphite-Epoxy Ion-Selective Electrode for the Determination of Iron(III) in Oxalic Medium

, &
Pages 417-427 | Received 16 Apr 1996, Accepted 20 Oct 1996, Published online: 21 Aug 2006
 

ABSTRACT

A coated graphite-epoxy iron(III) ion-selective electrode, based on the ion-pair between [Fe(oxalate)3]3− anion and tricaprylylmethylammonium cation (Aliquat 336) in a poly(vinylchloride) (PVC) matrix is constructed. A thin membrane film of this ion-pair, dibutylphthalate (DBPh) in PVC was deposited directly onto a PerspexR tube containing a graphite-epoxy conductor substrate attached to the end of a glass tube. The effect of membrane composition (ion pair, DBPh and PVC), oxalate concentration, pH and some cations and anions upon the electrode response is investigated. The electrode shows a linear anionic response to E vs. log[Fe3+] in the iron(III) concentration range from 2.9×10−6 to 10−2 mol/L, and a slope of −18.7±0.5 mV/dec, at pH working range 2-8 and 0.3 mol/L oxalate concentration. Variation in the potential of about ±2 mV was observed during a working day of 7-8 h. The response time was less than 5 sec and the lifetime of this electrode was superior to one year (over 1500 determinations by each polymeric membrane), with a practical detection limit of 2.1×10−6 mol/L. Application of this electrode for iron(III) determination in biotônico sample (Brazilian tonic formula) is described.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.