A Simple Dispersive Liquid-Liquid Microextraction for the Determination of Copper II in the Water Samples of the Halfaya Oil Field in Maysan

Abstract

Background: Copper, an important trace element for life on Earth, is crucial to many metabolic processes. This includes its role in the production and breakdown of nucleic acids and the metabolism of proteins, lipids, and carbohydrates. Objective: We aim to integrate DLLME with a spectrophotometric method to establish a novel approach for quantifying trace amounts of copper in water samples. Methods: In this study, a new ligand known as a 2-(4 aminophenol) benzimidazole azo derivative was successfully synthesized. This ligand was created by converting 2-(4-aminophenyl) benzimidazole into a diazonium salt and coupling it with 8-hydroxyquinoline in an alkaline environment. The resulting product was a brown azo dye, which served as the ligand for detecting copper (II) in aqueous samples. Results: To analyze copper (II) in both pure and aqueous samples, we developed and validated micro-extraction techniques combined with UV-Vis measurement. Specifically, we used the DLLME (dispersive liquid-liquid microextraction) method to separate, enrich, and assess copper (II) in both its pure form and in aqueous samples. UV-Vis spectroscopy at a wavelength of 503 nm was used for this purpose. We considered several variables during the experiment, including the type and volume of the dispersive solvent, the extraction solvents, the temperature, the reaction duration, and the centrifuging time. By optimizing these conditions, we achieved linear procedures within the concentration range of (1.0–25.0) and (2.0–25.0) μg/mL for spectroscopy and DLLME methods, respectively. For the spectroscopic and DLLME approaches, the coefficient of determination (R2) was found to be 0.9963 and 0.9979 for the spectrophotometric and DLLME methods, respectively. The limit of detection (LOD) for copper (II) was found to be 0.23 and 0.04 μg/mL, respectively. Moreover, the recovery of the target analyte in aqueous samples was found to be between 95.6% and 101% for the spectroscopy method and between 102.4% and 108.2% for the DLLME method. Conclusions: These results demonstrate the effectiveness and accuracy of both methods in analyzing copper (II) in aqueous samples.

Keywords

• Copper
• Microextraction
• DLLME
• Azo compound
• Green chemistry