title: Utilization of an ionic liquid in situ preconcentration method for the determination of the 15 + 1 European Union polycyclic aromatic hydrocarbons in drinking water and fruit-tea infusions.
abstract: An ionic liquid (IL) in situ preconcentration method was optimized and applied to the monitoring of the 15 + 1 European Union polycyclic aromatic hydrocarbons in water and fruit-tea infusions. The optimized method utilizes 10 mL of water (or infusion) containing 38 μL of the IL 1-butyl-3-methylimidazolium chloride and a content of 36.1 g/L NaCl, which are mixed with Li-NTf2 (340 μL, 0.2 g/mL), followed by vortex (4 min) and centrifugation (5 min). The obtained microdroplet containing hydrocarbons is diluted with acetonitrile and injected into an HPLC with UV/Vis and fluorescence detection. The method presented average enrichment factors of 127 for water (tap water and bottled water) and 27 for two fruit-tea infusions; with average relative recoveries of 86.7 and 106% for water and fruit-tea infusions, respectively. The method was sensitive, with detection limits ranging from 0.001 to 0.050 ng/mL in water, and from 0.010 to 0.600 ng/mL in fruit-tea infusions, for the fluorescent hydrocarbons. Real extraction efficiencies ranged from 12.7 to 58.7% for water, and from 20.2 to 117% for the infusions. The method was also fast (~12 min) and free of organic solvents in the extraction step.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Universidad de La Laguna, La Laguna, Tenerife, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Germán-Hernández
authors.forename: Pilar
authors.initials: P
authors.lastname: Crespo-Llabrés
authors.forename: Verónica
authors.initials: V
authors.lastname: Pino
authors.forename: Juan H
authors.initials: JH
authors.lastname: Ayala
authors.forename: Ana M
authors.initials: AM
authors.lastname: Afonso
mesh_terms: D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D060766:Drinking Water / Q000737:chemistry*; D005062:European Union; D005638:Fruit / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013662:Tea / Q000737:chemistry*
chemical_list: D060766:Drinking Water; D052578:Ionic Liquids; D011084:Polycyclic Aromatic Hydrocarbons; D013662:Tea
keywords: Fluorescence detection; HPLC; Ionic liquids; Polycyclic aromatic hydrocarbons; Preconcentration methods