In this study, a new azo reagent, 4-((6-methoxybenzodthiazol-2-yl) diazenyl)-3-hydroxy-2-naphthaldehyde (4-MTDHN), was synthesized and identified using UV-Vis, FTIR, 1H-NMR, and mass spectrometry. It was subsequently coupled with nickel ions to form an ion-pair complex, which was extracted using the cloud point extraction (CPE) method. The Ni–(4-MTDHN) structure was examined using the Job method; the molar ratio was found to be 1 : 1. The experimental parameters, like pH, the 4-MTDHN concentration, surfactant, metal ions, heating duration, and temperature, were optimized. Also, the thermodynamic parameters of the CPE were determined: ΔHex = +0.164 kJ mol–1, ΔGex = –68.819 kJ mol–1, and ΔSex = +195.421 J mol–1 K–1. An endothermic process is indicated by this method. The good analytical figures were obtained, such as a limit of detection (LOD) of 0.02 µg L–1, a limit of quantification (LOQ) of 0.86 µg L–1, a preconcentration factor (PF) of 12.5, an enrichment factor (EF) of 43.82, and an RSD of 0.017%. The calibration curve was found to be linear in the range of 10.0–100.0 µg L–1. Using the suggested approach, the impact of the electrolyte ions was also examined. The suggested approach was applied to various vegetable grains.
Al-awidee et al. (Sun,) studied this question.