Fernández Martínez, Elena, Vidal, Lorena, Canals, Antonio Hydrophilic magnetic ionic liquid for magnetic headspace single-drop microextraction of chlorobenzenes prior to thermal desorption-gas chromatography-mass spectrometry Analytical and Bioanalytical Chemistry. 2018, 410(19): 4679-4687. doi:10.1007/s00216-017-0755-2 URI: http://hdl.handle.net/10045/77137 DOI: 10.1007/s00216-017-0755-2 ISSN: 1618-2642 (Print) Abstract: A new, fast, easy to handle, and environmentally friendly magnetic headspace single-drop microextraction (Mag-HS-SDME) based on a magnetic ionic liquid (MIL) as an extractant solvent is presented. A small drop of the MIL 1-ethyl-3-methylimidazolium tetraisothiocyanatocobaltate(II) ([Emim]2[Co(NCS)4]) is located on one end of a small neodymium magnet to extract nine chlorobenzenes (1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,4,5-tetrachlorobenzene, and pentachlorobenzene) as model analytes from water samples prior to thermal desorption-gas chromatography-mass spectrometry determination. A multivariate optimization strategy was employed to optimize experimental parameters affecting Mag-HS-SDME. The method was evaluated under optimized extraction conditions (i.e., sample volume, 20 mL; MIL volume, 1 μL; extraction time, 10 min; stirring speed, 1500 rpm; and ionic strength, 15% NaCl (w/v)), obtaining a linear response from 0.05 to 5 μg L−1 for all analytes. The repeatability of the proposed method was evaluated at 0.7 and 3 μg L−1 spiking levels and coefficients of variation ranged between 3 and 18% (n = 3). Limits of detection were in the order of nanograms per liter ranging from 4 ng L−1 for 1,4-dichlorobenzene and 1,2,3,4-tetrachlorobenzene to 8 ng L−1 for 1,2,4,5-tetrachlorobenzene. Finally, tap water, pond water, and wastewater were selected as real water samples to assess the applicability of the method. Relative recoveries varied between 82 and 114% showing negligible matrix effects. Keywords:Magnetic ionic liquid, Magnetic headspace single-drop microextraction, Thermal desorption-gas chromatography-mass spectrometry, Chlorobenzenes, Water samples Springer Berlin Heidelberg info:eu-repo/semantics/article