Solvent effects in microemulsion electrokinetic chromatography

• Published in: Electrophoresis Vol. 24; no. 10; pp. 1537 - 1543
• Main Author: Klampfl, Christian W.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.05.2003; WILEY‐VCH Verlag
• Subjects: Chromatography, Micellar Electrokinetic Capillary - methods; Emulsions; Microemulsion electrokinetic chromatography; Organic Chemicals - chemistry; Review; Separation mechanism; Solvent effects; Solvents - chemistry; Surface-Active Agents - chemistry
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.200305379

The contribution of organic solvents to the mechanisms responsible for separation in microemulsion electrokinetic chromatography (MEEKC) is reviewed. Organic solvents are needed as constituents of microemulsions for a series of reasons. (i) A water‐immiscible organic substance is used to form the actual oil phase of the microemulsion, (ii) a less hydrophobic solvent is commonly employed as a so‐called cosurfactant, and (iii) in many cases an organic modifier is added to influence the solubility of the analytes in the aqueous phase of the microemulsion. All these organic solvents do not only participate in the separation in their actual function, but also interact with each other and the analytes. Variations in separation selectivities triggered by changes in the nature and/or concentration of these organic solvents present in microemulsions suitable for MEEKC are discussed in this work.