Investigation of trace element contents in edible oils sold in Turkey using microemulsion and emulsion procedures by graphite furnace atomic absorption spectrophotometry

In this study, Pb, Cu, Cr, Ni and Cd in edible oils (sun flower, corn, olive, hazel nut) sold in Turkey were determined by graphite furnace atomic absorption spectrophotometry (GFAAS) after formation of emulsions and microemulsions. In order to prepare the emulsions, 1.0 g of edible oil sample, 1.0 mL of toluene and 0.1 g Triton X-114 were mixed. The mixture was then completed to 10.0 mL with 0.2% HNO3. To prepare microemulsion of edible oil samples, 0.1 mL of concentrated HCl solution and 0.5 g of oil sample were mixed. The total volume of mixture was completed to 10 mL with propan-2-ol. The both emulsions were homogenized in ultrasonic bath for 5 min. The phase separation was not observed at least 1 week at room temperature. Aqueous standards were used for calibration. The limits of detection (LOD) obtained from emulsion and microemulsion were 10.9, 15.3, 24.9, 6.2, 4.2 ng g(-1) and 13.4, 16.2, 25.6, 9.1, 6.2 ng g(-1) for Pb, Cu, Cr, Ni, Cd, respectively. The analytical parameters such as LOD, sensitivity for emulsion are were better compared to those for microemulsion. (C) 2015 Elsevier Ltd. All rights reserved.