title: In-syringe-stirring: a novel approach for magnetic stirring-assisted dispersive liquid-liquid microextraction.
abstract: For the first time, the use of a magnetic stirrer within the syringe of an automated syringe pump and the resulting possible analytical applications are described. A simple instrumentation following roughly the one from sequential injection analyzer systems is used in combination with an adaptor, which is placed onto the barrel of a glass syringe. Swirling around the longitudinal axis of the syringe and holding two strong neodymium magnets, it causes a rotating magnetic field and serves as driver for a magnetic stirring bar placed inside of the syringe. In a first study it was shown that this approach leads to a sealed but also automatically adaptable reaction vessel, the syringe, in which rapid and homogeneous mixing of sample with the required reagents within short time can be carried out. In a second study in-a-syringe magnetic stirring-assisted dispersive liquid-liquid microextraction (MSA-DLLME) was demonstrated by the application of the analyzer system to fluorimetric determination of aluminum in seawater samples using lumogallion. A linear working range up to 1.1 μmol L(-1) and a limit of detection of 6.1 nmol L(-1) were found. An average recovery of 106.0% was achieved for coastal seawaters with a reproducibility of 4.4%. The procedure lasted 210 s including syringe cleaning and only 150 μL of hexanol and 4.1 mL of sample were required.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Horstkotte
authors.forename: Ruth
authors.initials: R
authors.lastname: Suárez
authors.forename: Petr
authors.initials: P
authors.lastname: Solich
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerdà
mesh_terms: D000535:Aluminum / Q000302:isolation & purification; D002021:Buffers; D004867:Equipment Design; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics; D015203:Reproducibility of Results; D012623:Seawater / Q000032:analysis; D013594:Syringes; D013997:Time Factors
chemical_list: D002021:Buffers; D000535:Aluminum
keywords: Aluminum; In-syringe magnetic stirring-assisted liquid–liquid microextraction; Lumogallion; Seawater; Single-drop extraction