title: On-column electrochemical detection for microchip capillary electrophoresis.
abstract: The development of a cellulose acetate decoupler for on-column electrochemical detection in microchip capillary electrophoresis is presented. The capillary based laser-etched decoupler is translated to the planar format to isolate the detector circuit from the separation circuit. The decoupler is constructed by aligning a series of 20 30-microm holes through the coverplate of the microchip with the separation channel and casting a thin film of cellulose acetate within the holes. The decoupler shows excellent isolation of the detection circuit for separation currents up to 60 microA, with noise levels at or below 1 pA at a carbon fiber electrode. Detection limits of 25 nM were achieved for dopamine. This decoupler design combines excellent mechanical stability, effective shunting of high separation currents, and ease of manufacture.
authors.affiliation: Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr., Lawrence, Kansas 66045, USA.
authors.forename: Damon M
authors.initials: DM
authors.lastname: Osbourn
authors.forename: Craig E
authors.initials: CE
authors.lastname: Lunte
mesh_terms: D002395:Catecholamines / Q000302:isolation & purification; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D004298:Dopamine / Q000302:isolation & purification; D004563:Electrochemistry; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D006873:Hydroquinones / Q000302:isolation & purification; D008832:Microchemistry
chemical_list: D002395:Catecholamines; D006873:Hydroquinones; C005062:acetylcellulose; D002482:Cellulose; D004298:Dopamine