Development of UV-Vis Spectrophotometric Method for Rapid Nickel Determination in Original Oil Matrix

A novel method for the determination of nickel in edible oils was proposed. The suggested procedure was on the basis of complexation of N, N’-bis(4-methoxysalicylidene) ethylenediamine and nickel in oily media and UV-Visible spectrophotometric determination at 396 nm. The complex formation was completed within 20 seconds. The mixture of n-hexane and acetone (1:4, v/v) was used as solvent and the molar absorptivity of the complex was calculated as 6540 L mol^-1 cm^-1.The limits of detection and quantification were 0.24 and 0.82 µg g^-1, respectively. The calibration graph was linear between 0.25-1.50 mg L^-1 nickel concentration with 0.9995 correlation coefficient. The reliability of the suggested method was tested by analysis of organometallic nickel standard and the recovery and relative standard deviation were found as 97.0 % and 3.8 %, respectively. Furthermore, the developed method was successfully applied on nickel spiked real samples and recovery values were between 90.0 - 104.0 %.