title: Microchip capillary electrophoresis/electrochemical detection of hydrazine compounds at a cobalt phthalocyanine modified electrochemical detector.
abstract: This article reports on the use of cobalt(II) phthalocyanine (CoPc)-modified carbon paste amperometric detector for monitoring hydrazine compounds following their microchip separation. The marked catalytic electrochemical properties of CoPc-modified electrode display enhanced sensitivity compared with unmodified carbon pastes at a relatively low detection potential (+0.5V versus Ag/AgCl). Factors influencing the on-chip separation and detection processes have been optimized. Three hydrazines (hydrazine, 1,1 dimethylhydrazine, and phenylhydrazine) have been separated within 130s at a separation voltage of 1kV using a 10mM phosphate run buffer (pH 6.5). The detection limits obtained from using the CoPc-modified carbon paste electrodes for hydrazine and phenylhydrazine are 0.5 and 0.7muM, respectively, with linearity over the 20-200muM range examined. Such miniaturization and speed advantages of microchip CE are coupled to the highly sensitivity and convenient preparation of CoPc-modified carbon paste electrode. The resulting microsystem should be attractive for field monitoring of toxic hydrazine compounds in environmental applications.
authors.affiliation: Department of Chemical & Materials Engineering, Chemistry and Biochemistry, and Biodesign Institute, Arizona State University, Tempe, AZ 85287-6006, USA; Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Weena
authors.initials: W
authors.lastname: Siangproh
authors.forename: Orawon
authors.initials: O
authors.lastname: Chailapakul
authors.forename: Rawiwan
authors.initials: R
authors.lastname: Laocharoensuk
authors.forename: Joseph
authors.initials: J
authors.lastname: Wang