Combining capillary electromigration with molecular imprinting techniques towards an optimal separation and determination.

Capillary electromigration is a well-established commercial group of analytical techniques, and, alike other column separation systems, it often benefits from a preceding sample preparation step. This step not only improves the analytical performance of many methods and prolongs the equipment's life span, but it also makes some determinations possible. A remarkable sample preparation technique is molecular imprinting technology: by creating tailored polymers able to 'select' the targeted analytes, matrix effects are severely diminished. This review aims to provide an overview of all the published works that combine capillary electrophoresis and molecularly imprinted polymers (MIP). Although a literature search produced around 130 published analytical methodologies and 5 patents, authors believe that there is still plenty of room for interesting developments. Works ranged from the analysis of pesticides to pharmaceuticals or hormones, being the most common instrumental detection spectrophotometric. The combination between MIP and electrophoresis can be divided into two main categories depending on where the MIPs are placed within the analytical 'pipeline': off-column and in-column. Off-column consisted of MIP batch application previous to capillary injection. In-column approaches are more complex, and can be divided into coating, monolith, packed (these three being considered capillary electrochromatography), and dispersed particles (affinity capillary electrophoresis).