Integrating continuous microflow reactions with subsequent micropreparative separations on a single microfluidic chip.

A current challenge in continuous flow chemistry using microfluidic devices is the combination with a micropreparative separation technique for online product clean-up and analysis. Herein we describe an approach for seamless on-chip integration of continuous flow reactors with a downstream separation functionality based on free-flow electrophoresis. A prototype device was fabricated via liquid phase lithography in a one-step procedure. This proof of concept was successfully validated by performing a model reaction of amino acids with ortho-phthaldialdehyde and continuous separation of the resulting products via micro free-flow zone electrophoresis.