ABSTRACT

The nickel (II) ion was determined, separated, and removed using the azo reagent 2-2-[phenylazo]doxycycline (PAD), which had previously been created by a coupling reaction. The metal was extracted as an ion-pair association complex by the cloud point extraction (CPE) technique into the surfactant-rich (organic) phase, and was subsequently estimated after the optimum conditions and the factors governing the extraction efficiency had been established. The ion-pair complex was monitored spectrophotometrically at λmax = 451 nm. Optimization of the complexation and extraction conditions gave the following optimum values: pH = 9, a Triton X-100 volume of 0.7 mL, a heating time of 10 min and an equilibration temperature of 80 °C. The thermodynamic parameters of the CPE process in the Triton X-100 phase were also evaluated and found to be ΔH = 0.15126 kJ, ΔG = −57.6472 kJ and ΔS = 163.7350 J mol-1 K-1, indicating a spontaneous, endothermic and entropy-driven process. The extracted compound was prepared in stoichiometric ratio of 1:1, (metal : ligand). The method was effectively utilised for the analysis and removal of nickel in fish, vegetables, plant leaves and water with a 10 mL sample volume under the optimised condition and good results were obtained.

KEYWORDS 

cloud point extraction; nickel(II); azo reagent; spectrophotometric determination; thermodynamics; water purification.

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Cite this article

Hamza, H. D., Kahait, H. S., & Ali, I. R. (2026). A Prepared Azo Reagent for Cloud Point Extraction, Spectrophotometric Determination, and Removal of Ni(II) from Environmental Samples. INTERNATIONAL JOURNAL OF HEALTH & MEDICAL RESEARCH, 5(8), 779-787. https://doi.org/10.58806/ijhmr.2026.v5i8n08