Extraction of nickel from edible oils with a complexing agent prior to determination by FAAS

In the present work, a new extraction method for separation of nickel from edible oils and determination by FAAS is reported. This method is based on extraction of Ni(II) ions from the oil to aqueous phase with N,N'-bis(4-methoxysalicylidene) ethylenediamine (MSE) and determination by FAAS. Properties of the complex formed between MSE and Ni(II) were investigated spectrophotometrically. Central composite design (CCD) was utilized for optimization of MSE to oil, stirring time and temperature, which were 0.97 mL g(-1), 15.4 min, and 29.7 degrees C, respectively. The developed method was tested with an oil-based metal standard and the recovery was 93.8 +/- 3.9%. The proposed method was applied with five different edible oils. (C) 2015 Elsevier Ltd. All rights reserved.