Development of Ultrasonic Assisted Modified Mixed Cloud Point Extraction (UA– MMCP) by Dispersion of ZnO Nanoparticles for Preconcentration and separation of Ni, Co, Cd in Environmental Sample

Contamination of water, soil and plants by heavy metal ions is of great concern due to their associated ecological and health toxic effects even at very low concentrations. Among them, Ni, CO, Cd are most toxic metals owing to their accumulative toxicity for the human body [1]. SPE is one of the pre-treatment methods for the preconcentration of trace analytes from a sample. The major advantages of solid phase extraction are the high selectivity and high enrichment factor that could be achieved with this technique. This method gives a higher concentration ratio of analytes than other separation methods [2]. Nowadays, nanomaterials have been shown to be one of the most promising adsorbents for preconcentration of the metal ions [3]. One of the specific properties of nanomaterials is their high surface areas, which could strongly chemisorb many substances and present very high adsorption capacities towards metal ions. Cloud point extraction (CPE) using micelle is a well-known methodology for designing new analytical procedures for different analytes. CPE is a safe and green methodology, which uses small amounts of surfactant that limit environmental pollution [4]. Their suggested method has illustrated that CPE can be used for concentration and recycling of NPs in aqueous media. In this research, a new method was purposed for cloud-point extraction along with scattering of modified ZnO nanoparticles with ligand and measuring the nickel, cobalt and cadmium in environmental samples. In this project, 2- benzofuran thiosemicarbazone and triton X-114 were used as complexing agent and surfactants respectively. The main factors, such as pH, ultrasonic time, temperature and nanoparticles size, that have a significant effect on the extraction, were determined and optimized using experimental design (Box- Behnken Design). In optimal conditions, the calibration graphs for cadmium, cobalt and nickel are obtained as in the ranges of 60-0.003 mg.L-1, 55-0.003 mg.L-1 and 45-0.005 mg.L-1 respectively. This method has been successfully obtained in the extraction in water samples.