Ionic liquid-based cloud point extraction for spectrophotometric determination of copper in water and food samples using a novel imidazole derivative

In this study, a new imidazole derivative, 2,2(1H-benzo[d]imidazole-1,2-diyl) diphenol (BIDP), was prepared as a chelation reagent. The framework of BIDP was identified by various spectroscopic methods such as UV-Vis, FTIR, 1H NMR, and 13C NMR. Following, BIDP was utilized to extract copper from water, fruits and vegetables using the ionic liquid-cloud point extraction approach (IL-CPE) with a spectrophotometric analyzer at room temperature. 1-octyl-3-methylimidazolium hexafluorophosphate [C8MIM] [PF6] was used as an ionic liquid (IL) to improve the extraction capability of TritonX-100. In addition, IL removes the heating step required to produce a cloudy solution. Experimental variables were investigated and improved to offer efficient copper recovery. The limit of detection (LOD), enrichment factor (EF), and linearity bands were 0.1 μg L−1, 90.5 and 0.3–600 μg L−1, respectively. The environmental practices for IL-CPE/UV-Vis were evaluated by two programs: Analytical Greenness Metric for Sample Preparation (AGREEprep) and Sample Preparation Metric of Sustainability (SPMS). The greenness scores obtained from the AGREEprep and SPMS programs were 0.75 and 6.95, respectively, making this method a green practice. Finally, this approach was used to measure copper in foods and refine it to enhance the quality and safety of food control initiatives.