title: On-line in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction HPLC--UV method for UV filters determination using 1-hexyl-3-methylimidazolium hexafluorophosphate as extractant.
abstract: An environmental friendly and fully automated method using in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography has been developed for the determination of UV filters in environmental water samples. The main "green" features on this method are the use of an ionic liquid as extracting solvent, avoiding the use of chlorinated solvents, and the on-line microextraction, preconcentration, separation and detection minimizing the use of reagents and so the waste generation. After sample treatment, 20 µL of the organic droplet was injected onto the HPLC-UV system. Various parameters affecting the extraction efficiency were studied using multivariate optimization approach, including the quantity of extraction and dispersive solvents, extraction and sedimentation time, ionic strength and pH. Under optimized conditions, limits of detection were within the range of 0.08-12 µg/L, for 3.5 mL sample volume. Linearity ranges were up to 500 µg/L for the UV-filters studied. Furthermore, enrichment factors ranging from 11 to 23 folds were obtained. Intra- and inter-assay precisions were 6% and 8%, respectively. Finally, the proposed method was successfully applied to determine UV filters in surface seawater and swimming pool samples attaining satisfactory recoveries over the range of 89-114% and 86-107%, respectively.
authors.affiliation: Laboratory of Environmental Analytical Chemistry - LQA2, University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain. Electronic address: ruteta@gmail.com.
authors.forename: Ruth
authors.initials: R
authors.lastname: Suárez
authors.affiliation: Laboratory of Environmental Analytical Chemistry - LQA2, University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Clavijo
authors.affiliation: Sciware Systems, S.L., Spin-off of the University of the Balearic Islands, C/Pi 37, 07193 Bunyola, Spain.
authors.forename: Jessica
authors.initials: J
authors.lastname: Avivar
authors.affiliation: Laboratory of Environmental Analytical Chemistry - LQA2, University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain; Sciware Systems, S.L., Spin-off of the University of the Balearic Islands, C/Pi 37, 07193 Bunyola, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerdà
keywords: Environmental water analysis; HPLC-UV; In-syringe magnetic stirring assisted dispersive liquid–liquid microextraction; Ionic liquids; On-line coupling; UV filters