Capabilities of ionic liquids for chromatographic and non-chromatographic separation in elemental speciation analysis

WUILLOUD, RODOLFO G.

Águas de Lindóia

Encuentro; 5º ENCONTRO BRASILEIRO SOBRE ESPECIAÇÃO QUÍMICA; 2017

Universidade Estadual Paulista

Trace elements speciation is nowadays considered as crucial knowledge to evaluate food safety, environmental processes and biological effects. It is becoming an important need for quality control and regulatory implementation by many countries. In part this is because the evaluation of total level of trace elements does not guarantee the safety of foods, since species often differ considerably in their effects, which can range from beneficial to highly toxic.Elemental speciation demands highly selective and sensitive analytical methods. These characteristics can be achieved by a combination of a selective separation method with a sensitive detection technique. Although any kind of separation technique is feasible, chromatographic techniques are easily coupled to elemental specific detectors. Likewise, non-chromatographic separation techniques can also be used for speciation analysis, but with a more limited separation power. In any case, much research is being undergoing to improve chromatographic and non-chromatographic techniques due to the high complexity of the speciation of some elements and difficulty of sample matrices, which needs of higher separation capabilities, short time and unequivocal identification of species.Ionic Liquids (ILs) are modern chemical entities with remarkable properties such as low volatility, high conductivity, and the possibility of offering several types of chemical interactions with different chemical species. Therefore, they have found much application in analytical chemistry. In fact, ILs have been proposed as highly efficient extractant phases for separation and preconcentration, while special interaction with solutes show them as excellent alternatives in chromatography too. In this lecture, recent advances on the development of non-chromatographic and chromatographic separation methods using ILs for elemental speciation analysis will be presented. Non-chromatographic methods based on modern liquid-liquid and solid-phase microextraction techniques with ILs (e.g. dispersive liquid-liquid microextraction (DLLME) and dispersive micro-solid phase extraction (D--SPE)) will be discussed. Furthermore, new dimensions obtained in HPLC separation of elemental species by implementing ILs will be presented, along with the benefits and potential drawbacks of their application when they are coupled to atomic spectrometry-based techniques.