title: Performance of an in-plane detection cell with integrated waveguides for UV/Vis absorbance measurements on microfluidic separation devices.
abstract: A microfluidic device with integrated waveguides and a long path length detection cell for UV/Vis absorbance detection is presented. The 750 microm U-cell detection geometry was evaluated in terms of its optical performance as well as its influence on efficiency for electrophoretic separations in the microdevice. Stray light was found to have a strong effect on both, the sensitivity of the detection and the available linear range. The long path length U-cell showed a 9 times higher sensitivity when compared to a conventional capillary electrophoresis (CE) system with a 75 microm inner diameter (ID) capillary, and a 22 times higher sensitivity than with a 50 microm ID capillary. The linear range was comparable to that achieved in a 75 microm ID capillary and more than twice as large as in a 50 microm ID capillary. The use of the 750 microm U-cell did not contribute significantly to band broadening; however, a clear quantification was made difficult by the convolution of several other band broadening sources.
authors.affiliation: MIC-Mikroelektronik Centret, Technical University of Denmark, DK-8000 Lyngby, Denmark.
authors.forename: Nickolaj J
authors.initials: NJ
authors.lastname: Petersen
authors.forename: Klaus B
authors.initials: KB
authors.lastname: Mogensen
authors.forename: Jörg P
authors.initials: JP
authors.lastname: Kutter
mesh_terms: D000042:Absorption; D000082:Acetaminophen / Q000302:isolation & purification; D001205:Ascorbic Acid / Q000302:isolation & purification; D002110:Caffeine / Q000302:isolation & purification; D005591:Chemical Fractionation; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D007660:Ketoprofen / Q000032:analysis; D008904:Miniaturization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000082:Acetaminophen; D002110:Caffeine; D007660:Ketoprofen; D001205:Ascorbic Acid