Application of Cloud Point Extraction for Copper,Nickel, Zinc and Iron Ions in Environmental Samples

A cloud point extraction procedure was presented for the preconcentration of copper, nickel, zinc and iron ions in various samples. After complexation by 2‐(6‐(1H‐benzod]imidazol‐2‐yl)pyridin‐2‐yl)‐1H‐benzod]Imidazole (BIYPYBI), analyte ions are quantitatively extracted in Triton X‐114 following centrifugation. 1.0 mol L^?1 HNO₃ nitric acid in methanol was added to the surfactant‐rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for BIYPYBI, Triton X‐114 and HNO₃ and bath temperature, centrifuge rate and time were optimized. Detection limits for Cu²⁺, Fe³⁺, Zn²⁺ and Ni²⁺ ions was 1.4, 2.2, 1.0 and 1.9 ng mL^?1, respectively. The preconcentration factors for all ions was 30, while the enrichment factor of Cu²⁺, Fe³⁺, Zn²⁺ and Ni²⁺ ions was 35, 25, 39 and 30, respectively. The proposed procedure was applied to the analysis of real samples.