title: On-line coupling of ionic liquid-based single-drop microextraction with capillary electrophoresis for sensitive detection of phenols.
abstract: An ionic liquid-based single-drop microextraction (IL-SDME) procedure using IL as an extractant on-line coupled to capillary electrophoresis (CE) is proposed. The method is capable of quantifying trace amounts of phenols in environmental water samples. For the SDME of three phenols, a 2.40 nL IL microdrop was exposed for 10 min to the aqueous sample and then was directly injected into the capillary column for analysis. Extraction parameters such as the extraction time, the IL single-drop volume, pH of the sample solution, ionic strength, volume of the sample solution and the extraction temperature were systematically investigated. Detection limits to three phenols were less than 0.05 microg mL(-1), and their calibration curves were all linear (R(2) > or = 0.9994) in the range from 0.05 to 50 microg mL(-1). And enrichment factors for three phenols were 156, 107 and 257 without agitation, respectively. This method was then utilized to analyze two real environmental samples from Yellow River and tap water, obtaining satisfactory results. Compared with the usual SDME for CE, IL-SDME-CE is a simple, low-cost, fast and environmentally friendly preconcentration technique.
authors.affiliation: Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Hongdeng
authors.initials: H
authors.lastname: Qiu
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.forename: Shengxiang
authors.initials: S
authors.lastname: Jiang
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D000432:Methanol; D010316:Particle Size; D010636:Phenols / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D012680:Sensitivity and Specificity; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000032:analysis
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D007093:Imidazoles; D052578:Ionic Liquids; D010636:Phenols; D014874:Water Pollutants, Chemical; D000432:Methanol