Electrokinetic preconcentration

The miniaturized separation techniques suffer from a lack of sensitivity, due to the low injected sample amount and/or weak optical path-length in UV absorbance. This drawback is emphasized as numerous application fields are concerned by trace-level analysis of some relevant analytes present in highly complex matrices. Therefore, it is necessary to significantly improve the limits of detection of the analytical process, especially when targeted compounds are at trace-level.

One approach consists in carrying out a preconcentration step of the analytes before their separation and detection. Capillary electrophoresis offer various strategies to involve in situ preconcentration steps, using unique electrokinetic properties of this technique, without any modification of the CE apparatus. Our lab is well-known for the development and use of these different electrokinetic preconcentration modes such as the ones based on :

• field-amplified sample stacking (FASS) and field-enhanced sample injection (FESI)
• transient-isotachophoresis (t-ITP)
• sweeping
• hyphenation of FESI and t-ITP: electrokinetic supercharging
• hyphenation of FESI and sweeping

Collaborations : DGA, Laboratoire Central de la Préfecture de Police de Paris, Université de Berne, University of Tasmania

Publications :

• Potential of long chain ionic liquids for on-line sample concentration techniques: application to micelle to solvent stacking, J. P. Quirino et al, J. Chromatogr. A 1218 (2011) 5718-5724

• A chemometric approach for the elucidation of the parameter impact in the hyphenation of fied-enhanced sample injection and seeping in capillary electrophoresis, P. Anres et al, Electrophoresis 33 (2012) 1169-1181

• Influence of high-conductivity buffer composition on field-enhanced sample injection coupled to sweeping in CE, P. Anres et al, Electrophoresis 34 (2013) 353-362