Performance of an in-plane detection cell with integrated waveguides for UV/Vis absorbance measurements on microfluidic separation devices.
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.
Petersen
Nickolaj J
NJ
MIC-Mikroelektronik Centret, Technical University of Denmark, DK-8000 Lyngby, Denmark.
Mogensen
Klaus B
KB
Kutter
Jörg P
JP
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
D000082:Acetaminophen; D002110:Caffeine; D007660:Ketoprofen; D001205:Ascorbic Acid