title: Selective ionic liquid ferrofluid based dispersive-solid phase extraction for simultaneous preconcentration/separation of lead and cadmium in milk and biological samples.
abstract: For the first time, a selective ionic liquid ferrofluid has been used in dispersive solid phase extraction (IL-FF-D-SPE) for simultaneous preconcentration and separation of lead and cadmium in milk and biological samples combined with flame atomic absorption spectrometry. To improve the selectivity of the ionic liquid ferrofluid, the surface of TiO2 nanoparticles with a magnetic core as sorbent was modified by loading 1-(2-pyridylazo)-2-naphtol. Due to the rapid injection of an appropriate amount of ionic liquid ferrofluid into the aqueous sample by a syringe, extraction can be achieved within a few seconds. In addition, based on the attraction of the ionic liquid ferrofluid to a magnet, no centrifugation step is needed for phase separation. The experimental parameters of IL-FF-D-SPE were optimized using a Box-Behnken design (BBD) after a Plackett-Burman screening design. Under the optimum conditions, the relative standard deviations of 2.2% and 2.4% were obtained for lead and cadmium, respectively (n=7). The limit of detections were 1.21 µg L(-1) for Pb(II) and 0.21 µg L(-1) for Cd(II). The preconcentration factors were 250 for lead and 200 for cadmium and the maximum adsorption capacities of the sorbent were 11.18 and 9.34 mg g(-1) for lead and cadmium, respectively.
authors.affiliation: Department of Analytical Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Negin
authors.initials: N
authors.lastname: Fasih Ramandi
authors.affiliation: Department of Analytical Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran. Electronic address: shemiran@khayam.ut.ac.ir.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Shemirani
mesh_terms: D000818:Animals; D002104:Cadmium / Q000032:analysis* / Q000302:isolation & purification; D002417:Cattle; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D052578:Ionic Liquids / Q000737:chemistry*; D007854:Lead / Q000032:analysis* / Q000302:isolation & purification; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D044967:Serum / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D013054:Spectrophotometry, Atomic; D014025:Titanium; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005290:Ferric Compounds; D052578:Ionic Liquids; D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical; D002104:Cadmium; C009495:titanium dioxide; D007854:Lead; D014025:Titanium
keywords: Box–Behnken design.; Ionic liquid-ferrofluid based dispersive-solid phase extraction; Magnetic nanoparticles; Selective Ionic liquid-Ferrofluid; TiO(2) coated magnetic nanoparticles modified by 1-(2-pyridylazo)-2-naphtol