A sensitive and selective deep eutectic solvent-based ultrasound-assisted liquid phase microextraction procedure for separation-preconcentration and determination of copper in olive oil and water samples

A green and simple deep eutectic solvent-based ultrasound-assisted liquid phase microextraction method has been developed for the preconcentration of copper as 2-(5-bromo-2-pyridylazo)-5-(diethylamino) phenol chelates. The effects of pH, ligand concentration, DES volume, sample volume, and tetrahydrofuran volume were investigated. Analytical performance parameters like limit of detection, limit of quantification, preconcentration factor, and relative standard deviation were determined as 6.6 mu g L-1, 21.8 mu g L-1, 15, and <5%, respectively. Validation of the developed method was checked by the analysis of certificated reference materials. The procedure was successfully applied to determination of copper in olive oil and water samples.