Electrophoretic method for the determination of sulfonylureas in grain samples using a continuous flow system for SPE step and ionic liquid with dispersed carbon nanotubes as electrolyte solution

VALERIA H. SPRINGER; FRANCISCO APRILE; ADRIANA G. LISTA

Congreso; 12th International Conference on Flow Analysis; 2012

Solid phase extraction (SPE) is a widely used technique in analytical sciences to carry out the preconcentration of analytes or/and the clean-up of complex samples. Also, it is possible to automate and simplify this pretreatment procedure using continuous flow systems which can be coupled in the on/off- line mode to CE systems. In the last years, ionic liquids (ILs) have been used as ?green solvents? because of their unique properties, thus replacing the traditional organic solvents[1]. Specially, room temperature ionic liquids (RTILs) are employed in different separation techniques, including CE among others [2,3]. On the other hand, carbon nanotubes (CNTs) have been applied in analytical chemistry due to their special physical/chemical properties which make them suitable for a wide range of applications [4, 5]. The purpose of the present work is to develop an electrophoretic method to determine sulfonylurea herbicides (SUs) in grain samples. Ionic liquids are proposed as main component of the separation solution in order to replace the commonly used electrolyte solutions. Moreover, single walled carbon nanotubes (SWCNTs) are included as additive into the background electrolyte solution (BGE) with the aim to improve the resolution between analyte peaks. A simple SPE continuous flow system was developed for the preconcentration of analytes before CE-UV analysis.