Abstract
Separation and preconcentration procedures are often necessary in order to eliminate interfering substances, increased sensitiveness and higher detection limits. These procedures include a liquid-phase extraction, solid-phase extraction, co-precipitation and precipitation. The traditional liquid-liquid extraction (batch) provides a number of applications in determining multiples types of analytes, both in low concentrations and complex matrices such as, for example, in the environment, beverages and biological matrices. The high consumption of toxic solvents can be translated as an advantage for this kind of extraction, as such solvents present a certain level of harmfulness to human beings and the environment. Dispersive liquid-liquid microextraction (DLLME) is, therefore, a proposal to reduce, or even eliminate, the use of toxic solvents. Since when it was initially proposed in 2006, DLLME has been combined with various detection techniques to determine several kinds of analytes (organic and inorganic). This can be achieved by introducing a small amount of extractant solvent either mixed or not with a dispersive solvent to the object sample, generally in aqueous medium. Even if in a smaller amount, a number of DLLME procedures use chlorinated solvents, and as a result of their high level of toxicity, there have been some alternative solvents which are less harmful, such as long-chain alcohols. Extractant solvent can be dispersed by using a dispersive solvent (soluble in aqueous medium and extractant solvent), generally ethanol, methanol, acetone, among others, or by means of vortex or ultrasound agitation, for instance. This project has the main goal to use DLLME in the development of analytical methods for determining low-concentration metals and non-metals, as well as complex matrices. Taking all the advantages provided by DLLME, we can: (i) evaluate the use of different extracting solvents with lower toxicity possible; and different dispersive solvents, or the elimination of the latter; (ii) exploit the advantages of DLLME combined with other micro(extraction) procedures aiming at LIBS detection or other methods aiming the direct solid analysis; and (iii) combine DLLME with different detection techniques, spectrometric and voltametric. (AU)
Scientific publications(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
LEME, FLAVIO O.;
LIMA, LUCAS CARVALHO;
PAPAI, RODRIGO;
AKIBA, NAOMI;
BATISTA, BRUNO LEMOS;
GAUBEUR, IVANISE.
A novel vortex-assisted dispersive liquid-phase microextraction procedure for preconcentration of europium, gadolinium, lanthanum, neodymium, and ytterbium from water combined with ICP techniques.
Journal of Analytical Atomic Spectrometry,
v. 33,
n. 11,
p. 2000-2007,
NOV 1 2018.
Web of Science Citations: 3.