title: Iron species determination by task-specific ionic liquid-based in situ solvent formation dispersive liquid-liquid microextraction combined with flame atomic absorption spectrometry.
abstract: BACKGROUND
  The task-specific ionic liquid (TSIL) of 1-ethyl-3-methylimidazolium bromide functionalized with 8-hydroxyquinoline was used as a chelating agent and extracting solvent for dispersive liquid-liquid microextraction and subsequent determination of Fe(III) by flame atomic absorption spectrometry. The in situ solvent formation of TSIL using KPF6provided the desired water-immiscible ionic liquid. The total Fe concentration could be determined after pre-oxidation of Fe(II) to Fe(III). Various factors affecting the proposed extraction procedure were optimized.
  
  
  RESULTS
  The proposed analytical conditions were: sample pH 5, TSIL amount 0.3% (w/v), KPF6amount 0.15% (w/v), anti-sticking 0.1% (w/v) and salt concentration 5% (w/v). Under optimal conditions, the linear dynamic ranges for Fe(III) and total Fe were 20-80 and 20-110 ng mL-1, respectively, with a detection limit of 6.9 ng mL-1for Fe(III) and relative standard deviation of 2.2%. The proposed method was successfully applied to the determination of trace Fe(III) in water (underground, tap, refined water and artificial sea water) and beverage (apple, tomato, and tea) samples.
  
  
  CONCLUSIONS
  The developed method offers advantages such as simplicity, ease of operation, and extraction of Fe(III) from aqueous solutions without the use of organic solvent. It was successfully applied for iron speciation in different real samples. © 2017 Society of Chemical Industry.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Birjand, Birjand, South khorasan, Iran.
authors.forename: Susan
authors.initials: S
authors.lastname: Sadeghi
authors.affiliation: Department of Chemistry, Faculty of Science, University of Birjand, Birjand, South khorasan, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Ashoori
mesh_terms: D001628:Beverages / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry; D007501:Iron / Q000737:chemistry* / Q000302:isolation & purification*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D052578:Ionic Liquids; D014874:Water Pollutants, Chemical; D007501:Iron
keywords: 8-hydroxyquinoline-functionalized ionic liquid; dispersive liquid-liquid microextraction; flame atomic absorption spectrometry; iron speciation; water and beverage samples