Abstract
An environmentally friendly, sensitive, easy and fast ultrasound-assisted ionic liquid-based dispersive liquid-liquid microextraction technique (UA-IL-DLLME) was developed to preconcentrate trace quantities of nickel Ni(II) ion in water, food and tobacco samples prior to detection by FAAS. The proposed technique based on utilisationthe of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for Ni(II) ions after the complexation with quinalizarin (Quinz) at pH 6.0. The impact of different analytical parameters on the microextraction efficiency was investigated. In the range of 2.0-300 µg L
−1
, the calibration graph was linear. Limit of detection and preconcentration factor were 0.6 µg L
−1
and 100. Relative standard deviation (RSD%) as precision at 50 and 100 µg L
−1
of Ni(II) were 2.4% and 3.6%, respectively (n = 10). The validation of the proposed procedure was verified by a test of two certified reference materials (TMDA-51.3 fortified water, TMDA-53.3 fortified water and SRM spinach leaves 1570A) applying the standard addition method. Finally, the proposed UA-IL-DLLME method was developed and applied to preconcentrate and determine of trace quantities of Ni(II) in real water, food and tobacco samples with satisfactory results.