Currently, the research has been highly focused on the field of the environment, especially

the contamination of CPs in water (De Morais, Stoichev, selleck screening library Basto, & Vasconcelos, 2012). However, the migration and transformation of chlorophenols to foods drew more attention during very recent years (Campillo et al., 2010, Campillo et al., 2006, Diserens, 2001, Maggi et al., 2008, Martínez-Uruñuela et al., 2004, Martínez-Uruñuela et al., 2005, Röhrig and Meisch, 2000 and Veningerová et al., 1997). Various methods for the analysis of CPs in environmental samples have been proposed, mainly based on chromatographic separation. In most cases, a previous preconcentration/cleaning step is necessary, which has been well reviewed by Morais (De Morais, Stoichev, Basto, & Vasconcelos, 2012). However, even using preconcentration, some of the methods presented relatively high limits of detection (LODs) and, therefore, more efficient methods are still imperative. Dispersive liquid–liquid microextraction (DLLME) developed by (Rezaee et al., 2006) is a successful extraction technique due to the high contact surface of fine droplets of extractant solvent and analytes, which speeds up the mass-transfer processes

of analytes. DLLME is useful because of its high preconcentration factor, high extraction efficiency, and minimum requirements for sample and organic solvents. To date, it has undergone a number of modifications (Trujillo-Rodríguez, Rocío-Bautista, Pino, & Afonso, 2013). Ionic liquids (ILs) are ionic, non-molecular solvents with low melting points, negligible vapour pressures, and high thermal stability. Their unique solvation properties giving ILs unique selectivity and AZD2281 in vivo diverse separation mechanism, coupled to the fact that they can be structurally tailored 5-Fluoracil ic50 for specific applications. Their miscibility in water and organic solvents can be controlled by selecting the cation/anion combination or by incorporating certain functional groups in the IL molecule (Trujillo-Rodríguez

et al., 2013). There have been increased interests in exploiting the unique physicochemical properties of ILs in different extraction and microextraction schemes in recent years (Martín-Calero, Pino, & Afonso, 2011). The in-situ solvent formation for microextraction based on ILs (simplified as in-situ IL-DLLME) is utilising a hydrophilic IL as extractant solvent of the analytes contained in the aqueous solution. An anion-exchange reagent is then added to promote a metathesis reaction, and the hydrophilic IL is transformed into a hydrophobic IL, which settles to contain the preconcentrated analytes (Trujillo-Rodríguez et al., 2013). This in-situ IL-DLLME procedure avoids the utilisation of a dispersive organic solvent normally required in conventional DLLME or reduces the volume of dispersive organic solvent. The in-situ ionic exchange reaction and the extraction process can be completed within a very short time with high extraction efficiency.