Ionic Liquids in modern microextraction techniques for trace analysis

WUILLOUD, RODOLFO G.

Campos Do Jordao

Congreso; 16th ANALYTICAL CHEMISTRY NATIONAL MEETING; 2011

University of Sao Paulo

Separation and preconcentration are considered important steps within the total analytical process, as they afford elimination or minimization of matrix effects and concomitants along with enrichment of analytes, thus enhancing detection limits and sensitivity of detection techniques focused on trace element determination and speciation. One of the most decisive turning points in analytical science has been signaled by the introduction of the dimension of green chemistry into the assessment of analytical methods. Some of the principles of green chemistry, such as prevention of waste generation, the use of safer solvents, and the development of miniaturized methods are directly related to emerging techniques pursuing total and speciation metal analysis.[1] Ionic Liquids (ILs) are generally considered to be environmentally friendlier than common organic solvents and have unique characteristics (e.g. no effective vapor pressure, adjustable viscosity and miscibility in aqueous phases).[2] Moreover, they have been proposed as highly efficient extractant phases to improve analyte selectivity and sensitivity, turning them into important tools for chromatographic and spectrometric analysis.[3] Therefore, combination of these novel solvents with techniques aiming miniaturization of reagents and wastes could provide significant benefits for preserving our environment when analyses are developed. In this lecture, state-of-the-art applications of ILs in analytical chemistry with special emphasis on metal determination and speciation analysis are presented. Modern microextraction techniques based on ILs including, dispersive liquid-liquid microextraction (DLLME), single-drop microextraction (SDME), on-line LLME, etc., are discussed as well as their application in combination with atomic spectrometry-based techniques. [1] S. Armenta, S. Garrigues, M. de la Guardia, TrAC Trends in Analytical Chemistry, 27 (2008) 497. [2] R.D. Rogers, K.R. Seddon, Science, 302 (2003) 792. [3] E.M. Martinis, P. Berton, R.P. Monasterio, R.G. Wuilloud, TrAC - Trends in Analytical Chemistry, 29 (2010) 1184.