title: Ionic liquid-based liquid-phase microextraction, a new sample enrichment procedure for liquid chromatography.
abstract: Room temperature ionic liquids (RTILs) were used as extraction solvent in liquid-phase microextraction (LPME) coupled with liquid chromatography. Using 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) as extraction solvent, some parameters related to LPME of 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP) were optimized. Although [C6MIM][PF6] can suspend a much larger volume of drop on the needle of the microsyringe than the conventional solvents such as 1-octanol and carbon tetrachloride, the method sensitivity was analyte dependent because of the different partition coefficients and the relatively large viscosity of [C6MIM][PF6]. The proposed procedure has a detection limit and enrichment factor of 0.3 microg l(-1) and 163 for 4-NP, and 0.7 microg l(-1) and 130 for 4-t-OP, respectively. Aqueous samples including tap water, river water, and effluent from sewage treatment plant were analyzed by the proposed method and the recoveries at 10 microg l(-1) spiked level were in the range of 90-113%.
authors.affiliation: Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China.
authors.forename: Jing-fu
authors.initials: JF
authors.lastname: Liu
authors.forename: Yu-guang
authors.initials: YG
authors.lastname: Chi
authors.forename: Gui-bin
authors.initials: GB
authors.lastname: Jiang
authors.forename: Chao
authors.initials: C
authors.lastname: Tai
authors.forename: Jin-feng
authors.initials: JF
authors.lastname: Peng
authors.forename: Jing-Tian
authors.initials: JT
authors.lastname: Hu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007477:Ions / Q000737:chemistry; D007525:Isoelectric Focusing; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D013048:Specimen Handling; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D007477:Ions; D012997:Solvents; D014867:Water