title: Magnetic ionic liquids as non-conventional extraction solvents for the determination of polycyclic aromatic hydrocarbons.
abstract: This work describes the applicability of magnetic ionic liquids (MILs) in the analytical determination of a group of heavy polycyclic aromatic hydrocarbons. Three different MILs, namely, benzyltrioctylammonium bromotrichloroferrate (III) (MIL A), methoxybenzyltrioctylammonium bromotrichloroferrate (III) (MIL B), and 1,12-di(3-benzylbenzimidazolium) dodecane bis[(trifluoromethyl)sulfonyl)]imide bromotrichloroferrate (III) (MIL C), were designed to exhibit hydrophobic properties, and their performance examined in a microextraction method for hydrophobic analytes. The magnet-assisted approach with these MILs was performed in combination with high performance liquid chromatography and fluorescence detection. The study of the extraction performance showed that MIL A was the most suitable solvent for the extraction of polycyclic aromatic hydrocarbons and under optimum conditions the fast extraction step required ∼20 μL of MIL A for 10 mL of aqueous sample, 24 mmol L(-1) NaOH, high ionic strength content of NaCl (25% (w/v)), 500 μL of acetone as dispersive solvent, and 5 min of vortex. The desorption step required the aid of an external magnetic field with a strong NdFeB magnet (the separation requires few seconds), two back-extraction steps for polycyclic aromatic hydrocarbons retained in the MIL droplet with n-hexane, evaporation and reconstitution with acetonitrile. The overall method presented limits of detection down to 5 ng L(-1), relative recoveries ranging from 91.5 to 119%, and inter-day reproducibility values (expressed as relative standard derivation) lower than 16.4% for a spiked level of 0.4 μg L(-1) (n = 9). The method was also applied for the analysis of real samples, including tap water, wastewater, and tea infusion.
authors: Departamento de Química (Área de Química Analítica), Universidad de La Laguna (ULL), La Laguna, Tenerife, 38206, Spain. Electronic address: mtrujill@ull.edu.es.
authors: María J
authors: MJ
authors: Trujillo-Rodríguez
authors: Department of Chemistry, Iowa State University, Ames, IA, 50011, USA. Electronic address: onacham@iastate.edu.
authors: Omprakash
authors: O
authors: Nacham
authors: Department of Chemistry, Iowa State University, Ames, IA, 50011, USA. Electronic address: kdclark@iastate.edu.
authors: Kevin D
authors: KD
authors: Clark
authors: Departamento de Química (Área de Química Analítica), Universidad de La Laguna (ULL), La Laguna, Tenerife, 38206, Spain. Electronic address: veropino@ull.edu.es.
authors: Verónica
authors: V
authors: Pino
authors: Department of Chemistry, Iowa State University, Ames, IA, 50011, USA. Electronic address: andersoj@iastate.edu.
authors: Jared L
authors: JL
authors: Anderson
authors: Departamento de Química (Área de Química Analítica), Universidad de La Laguna (ULL), La Laguna, Tenerife, 38206, Spain. Electronic address: jayala@ull.edu.es.
authors: Juan H
authors: JH
authors: Ayala
authors: Departamento de Química (Área de Química Analítica), Universidad de La Laguna (ULL), La Laguna, Tenerife, 38206, Spain. Electronic address: aafonso@ull.es.
authors: Ana M
authors: AM
authors: Afonso
mesh_terms: D052578:Ionic Liquids / Q000737:chemistry*; D059627:Liquid Phase Microextraction; D060328:Magnetic Phenomena; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012997:Solvents / Q000737:chemistry
chemical_list: D052578:Ionic Liquids; D011084:Polycyclic Aromatic Hydrocarbons; D012997:Solvents
keywords: High-performance liquid chromatography; Ionic liquids; Magnetic ionic liquids; Magnetic-assisted microextraction; Polycyclic aromatic hydrocarbons