Unveiling iron chemical speciation in low sample volumes by a spectroelectrochemical approach

Cutillo-Foraster A., ÖZBEK N., Bastos-Arrieta J., Serrano N., Díaz-Cruz J. M.

Talanta, vol.307, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 307
  • Publication Date: 2026
  • Doi Number: 10.1016/j.talanta.2026.129768
  • Journal Name: Talanta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Chimica, Compendex
  • Keywords: Chemical speciation, Iron, Ortho-phenanthroline complexes, Screen-printed carbon electrodes, UV-Vis spectroelectrochemistry
  • Karadeniz Technical University Affiliated: Yes

Abstract

Spectroelectrochemistry (SEC) in the UV-vis region has shown interesting possibilities for analytical purposes, especially by means of chronoamperometric (CA) measurements in normal reflection mode using screen-printed carbon electrodes (SPCE). In this work, a study of the electrochemical and optical response of mixtures with different proportion of Fe(II)- and Fe(III)-ions complexed with ortho -phenanthroline (OP) was conducted by taking advantage of the appearance/disappearance of the intense red color of Fe(II)-OP complex as Fe(III) is reduced and Fe(II) is oxidized, respectively. As a proof of concept, the calibration curves obtained for mixtures under reduction (−0.2 V) and oxidation (+1.0 V) conditions were used to quantify the amount of Fe(II) and Fe(III) in a real sample. The analysis showed that the SEC-based strategy is a suitable tool for iron speciation using a reduced volume of sample.