food analysis: task specific ionic liquids for separation of nickel and cadmium from olive oil samples by thermal ultrasound-assisted dispersive multiphasic microextraction

In this study, a novel task-specific ionic liquid (tsils) was used for highly sensitive extraction and separation of nickel and cadmium in olive oil by thermal ultrasound-assisted dispersive multiphasic microextraction (tusadmpμe). by proposed method, a mixture containing of hydrophilic tsils (α- cyano-4-hydroxycinnamic acid diethylamine; [chca] [dea] and 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate; [hemim] [bf4]) as a complexing and extracting solvent, acetone as a dispersant of tsils was added to diluted olive oil with n-hexane containing cd (ii) and ni (ii) that was already complexed by tsils in 60°c at ph 6.0-7.5. after optimized conditions, the enrichment factor (ef), linear range (lr) and limit of detection (lod) were obtained (19.3; 19.6), (5.0- 415 μg l^-1; 2.7-92 μg l^-1) and (1.3 μg l^-1; 0.6 μg l^-1) with [chca] [dea] and (13.7; 14.2), (7.5- 600 μg l^-1; 3.6- 128 μg l^-1) and (2.2 ng l^-1; 0.9 μg l^-1) with [hemim][bf4] for ni and cd ions in olive oil samples respectively. in addition, the ions extraction with [chca] [dea] is more efficient than [hemim][bf4] by tusa-dmpμe method (less than 60%). moreover, the validation of methodology was achieved by standard oil by microwave digestion/etaas technique and spike samples with atom trap flame atomic absorption spectrometry (at-faas)