Enhanced adsorption/extraction of five typical polycyclic aromatic hydrocarbons from meat samples using magnetic effervescent tablets composed of dicationic ionic liquids and NiFe2O4 nanoparticles
Wei Zhang, Peipei Zhou, Wei Liu, Huili Wang, Xuedong Wang
Abstract
Owing to matrix complexity, the development of green and convenient pretreatment methods is crucial for routine monitoring of organic contaminants in meat samples. Dicationic ionic liquids (DILs) possess two active centers, thus resulting in superior physicochemical properties over monocationic species. Herein, the hydrophilic DILs and in-situ metathesis reaction salt were introduced into NiFe 2 O 4 -based magnetic effervescent tablets for enhancing adsorption/extraction of five typical polycyclic aromatic hydrocarbons (PAHs) in meats. Also, the synthesized NiFe 2 O 4 nanoparticles displayed larger specific surface area than others (CoFe 2 O 4 , Fe 3 O 4 and ZnFe 2 O 4 ), thereby supplying higher adsorption capacity for PAHs. The integration of DILs with NiFe 2 O 4 into magnetic effervescent tablets realized highly efficient adsorption/extraction, rapid magnetic separation/retrieval and CO 2 -induced vigorous dispersion into one synchronous step. After hydrolysis of the ground meat samples using 10 μM KOH, the filtered solution was diluted and subjected to magnetic effervescent tablet-assisted microextraction procedures. Optimized experimental variables were as follows: an effervescent tablet containing 0.7 g Na 2 CO 3 and NaH 2 PO 4 with molar ratio of 1:2; 60 mg [C 4 (MIM) 2 ]Br 2 ; 20 mg NiFe 2 O 4 ; 45 mg Na[N(CN) 2 ] and 500 μL toluene as elution solvent. The effervescent reaction-enhanced microextraction was combined with high performance liquid chromatography and fluorescence detection, rendering limits of detection as low as 0.01–0.07 μg kg −1 with high recoveries (82.3–104.7%) for five PAHs in raw, boiled, charcoal-grilled and smoked meats. To the best of our knowledge, this is the first report on the additive action between DILs and NiFe 2 O 4 in an effervescent reaction-enhanced microextraction, showing great analytical potential in meat matrices.