Spectrophotometry determination of Congo red in river water samples using nanosilver

• Published in: Toxicological and environmental chemistry Vol. 94; no. 10; pp. 1886 - 1892
• Main Authors: Sahraei, R, Farmany, A, Mortazavi, S.S, Noorizadeh, H
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 01.12.2012; Taylor & Francis Ltd
• Subjects: ascorbic acid; Calibration; Catalytic oxidation; chromium; Congo red; copper; detection limit; Dyes; Ethylene; Freshwater; Hydrochloric acid; ions; iron; Nanocomposites; Nanomaterials; nanosilver; Nanostructure; oxidation; potassium; river water; Rivers; Scientific imaging; Silver; silver nanoparticles; Spectrophotometry; temperature; Iran
• ISSN: 1029-0486; 0277-2248; 1029-0486
• DOI: 10.1080/02772248.2012.733397

A spectrophotometric procedure for the anionic diazo dye Congo red was proposed based on nanosilver catalyzed oxidation by potassium iodate in a hydrochloric acid medium. The calibration graph is linear for 0.8–240 mg L⁻¹, and the detection limit is 0.6 mg L⁻¹. Most foreign ions do not interfere with the determination, except for Cu(II), Fe(III), and Cr(VI). The interferences of Cu(II) and Fe(III) could be eliminated by masking with ethylene diamine tetraacetate, and that of Cr(VI) by reducing to Cr(III) with ascorbic acid. The typical features of this procedure are that it is sensitive for Congo red, and the determination could be carried out at room temperature. It had been used for the determination of Congo red in the Ganjnameh river water sample.