Ion-Pair-based Dispersive Liquid Liquid Microextraction Combined with Flame Atomic Absorption Spectrometry for a Sensitive Determination of Trace Amounts of Nickel in Food Samples

In this study, a sensitive method of dispersive liquid phase microextraction based on ion-pair combined with the flame atomic absorption spectrometry was proposed for the determination of trace Ni(II) using Aliquat 336-chloride as ion pair agent. Several factors which have effect on  the microextraction efficiency of Ni(II), such as pH, extraction and dispersive solvent type and their volume, concentration of the Aliquat 336-chloride, extraction time were investigated and the optimized experimental conditions were established. After extraction, the enrichment factor was 47. The detection limit of the method was 8.0 µg L-1 and the relative standard deviation for eight determinations of 100 µg L-1 Ni(II) was 2.1 %. The results for the determination of Ni(II) in food samples (black tea, lettuce, parsley and carrot) have demonstrated the accuracy, recovery and applicability of the proposed method.