title: Fabrication and performance of a three-dimensionally adjustable device for the amperometric detection of microchip capillary electrophoresis.
abstract: A microchip CE-amperometric detection (AD) system has been fabricated by integrating a two-dimensionally adjustable CE microchip and an AD cell containing a one-dimensionally adjustable disk detection electrode in a Plexiglas holder. It facilitates the precise 3-D alignment between the channel outlet and the detection electrode without a complicated 3-D manipulator. The performance of this unique system was demonstrated by separating five aromatic amines (1,4-phenyldiamine, aniline, 2-methylaniline, 4-chloroaniline, and 1-naphthylamine) of environmental concern. Factors influencing their separation and detection processes were examined and optimized. The five analytes have been well separated within 140 s in a 74 cm long separation channel at a separation voltage of +2500 V using a 10 mM phosphate buffer (pH 3.5). Highly linear response is obtained for the five analytes over the range 20-200 microM with the detection limits ranging from 0.46 to 1.44 microM, respectively. The present system demonstrated long-term stability and reproducibility with RSDs of less than 5% for the peak current (n = 9). The new approach for the microchannel-electrode alignment should find a wide range of applications in CE, flowing injection analysis, and other microfluidic analysis systems.
authors.affiliation: Department of Chemistry, Fudan University, Shanghai, China. gangchen@fudan.edu.cn
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Huiming
authors.initials: H
authors.lastname: Bao
authors.forename: Pengyuan
authors.initials: P
authors.lastname: Yang
mesh_terms: D015057:1-Naphthylamine / Q000302:isolation & purification; D000814:Aniline Compounds / Q000302:isolation & purification; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D005618:Fresh Water / Q000737:chemistry; D010655:Phenylenediamines / Q000302:isolation & purification; D014052:Toluidines / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D000814:Aniline Compounds; D010655:Phenylenediamines; D014052:Toluidines; D014874:Water Pollutants, Chemical; D015057:1-Naphthylamine; C023622:2-toluidine; C023650:aniline; C029728:4-phenylenediamine; C004658:4-chloroaniline