Integrated on-chip derivatization and electrophoresis for the rapid analysis of biogenic amines

• Published in: Electrophoresis 2004-07, Vol.25 (14), p.2363-2373
• Main Authors: Beard, Nigel P., Edel, Joshua B., deMello, Andrew J.
• Format: Article
• Language: English
• Subjects: Biogenic amines; Biogenic Amines - chemistry; Dichlorotriazine fluorescein; Electrophoresis, Capillary - methods; Fluorescein-5-isothiocyanate - chemistry; Fluorescent Dyes - chemistry; Microchip Analytical Procedures - methods; Microchip electrophoresis; Miniaturization
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.200305919

We demonstrate the monolithic integration of a chemical reactor with a capillary electrophoresis device for the rapid and sensitive analysis of biogenic amines. Fluorescein isothiocyanate (FITC) is widely employed for the analysis of amino‐group containing analytes. However, the slow reaction kinetics hinders the use of this dye for on‐chip labeling applications. Other alternatives are available such as o‐phthaldehyde (OPA), however, the inferior photophysical properties and the UV λmax present difficulties when using common excitation sources leading to a disparity in sensitivity. Consequently, we present for the first time the use of dichlorotriazine fluorescein (DTAF) as a superior in situ derivatizing agent for biogenic amines in microfluidic devices. The developed microdevice employs both hydrodynamic and electroosmotic flow, facilitating the creation of a polymeric microchip to perform both precolumn derivatization and electrophoretic analysis. The favorable photophysical properties of the DTAF and its fast reaction kinetics provide detection limits down to 1 nM and total analysis times (including on‐chip mixing and reaction) of