FAAS Determination of Trace Amount of Nickel in Water Samples with Cloud Point Extraction

Trace amount of Ni(Ⅱ) was extracted from water sample in the form of coordination complex with 1-(2-pyridylazo)-2-naphthol (PAN) at pH 7.0 by cloud point extraction with Triton X-100.The surfactant phase was dispersed in 0.5 mL of a mixture of conc.HNO3 and methanol in the ratio of 1 to 9 by volume,and the solution was introduced directly into the nebulizer for FAAS determination.Detection limit (3σ) of the method was found to be 3.77×10-3mg·L-1.The proposed method was used in the determination of nickel in a sample of river water,giving value of RSD′s (n=6) of 2.98%.