title: In-channel indirect amperometric detection of heavy metal ions for electrophoresis on a poly(dimethylsiloxane) microchip.
abstract: In-channel indirect amperometric detection mode for microchip capillary electrophoresis with positive separation electric field is successfully applied to some heavy metal ions. The influences of separation voltage, detection potential, the concentration and pH value of running buffer on the response of the detector have been investigated. An optimized condition of 1200V separation voltage, -0.1V detection potential, 20mM (pH 4.46) running buffer of 2-(N-morpholino)ethanesulfonic acid (MES)+l-histidine (l-His) was selected. The results clearly showed that Pb(2+), Cd(2+), and Cu(2+) were efficiently separated within 80s in a 3.7cm long native separation PDMS/PDMS channel and successfully detected at a single carbon fibre electrode. The theoretical plate numbers of Pb(2+), Cd(2+), and Cu(2+) were 1.2x10(5), 2.5x10(5), and 1.9x10(5)m(-1), respectively. The detection limits for Pb(2+), Cd(2+), and Cu(2+) were 1.3, 3.3 and 7.4muM (S/N=3).
authors.affiliation: State Key laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Key Lab of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Xin-Ai
authors.initials: XA
authors.lastname: Li
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Zhou
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen