Determination of copper with 5,5-dimethylcyclohexane-1,2,3-trione 1,2-dioxime 3-thiosemicarbazone in olive oils by adsorptive stripping square wave voltammetry

• Published in: Food chemistry 2006-05, Vol.96 (1), p.156-162
• Main Authors: Díaz, T. Galeano, Guiberteau, A., López Soto, M.D., Ortiz, J.M.
• Format: Article
• Language: English
• Subjects: 5,5-dimethylcyclohexane-1,2,3-trione 1,2-dioxime 3-thiosemicarbazone; adsorption; Biological and medical sciences; chemical concentration; Copper; detection; extraction; Fat industries; food composition; Food industries; Fundamental and applied biological sciences. Psychology; hydrochloric acid; measurement; Olive oil; reduction; semicarbazones; Stripping voltammetry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2005.04.014

In the present paper a method for the determination of Cu in olive oil samples by adsorptive stripping square wave voltammetry (Ad-SSWV) is presented. It has been proven that Cu reacts with 5,5-dimethylcyclohexane-1,2,3-trione 1,2-dioxime 3-thiosemicarbazone, DCDT, in strongly acid media giving rise to a complex. In Ad-SSWV the complex Cu–DCDT experiments an adsorptive reductive process which promotes the appearance of a peak at −0.570 V. The extraction process of Cu from olive oil is carried out with hot concentrated HCl. Calibration graph has been constructed from 0 to 35 ng mL −1 and the detection limit was 0.49 ng mL −1. The method has been applied to commercial olive oils samples and the amounts of Cu found are very similar to those obtained when samples are analysed by AAS.