title: Determination of heavy metal ions by microchip capillary electrophoresis coupled with contactless conductivity detection.
abstract: An integrated detection circuitry based on a lock-in amplifier was designed for contactless conductivity determination of heavy metals. Combined with a simple-structure electrophoresis microchip, the detection system is successfully utilized for the separation and determination of various heavy metals. The influences of the running buffer and detection conditions on the response of the detector have been investigated. Six millimole 2-morpholinoethanesulfonic acid + histidine were selected as buffer for its stable baseline and high sensitivity. The best signals were recorded with a frequency of 38 kHz and 20 V(pp). The results showed that Mn(2+), Cd(2+), Co(2+), and Cu(2+) can be successfully separated and detected within 100 s by our system. The detection limits for five heavy metals (Mn(2+), Pb(2+), Cd(2+), Co(2+), and Cu(2+)) were determined to range from about 0.7 to 5.4 μM. This microchip system performs a crucial step toward the realization of a simple, inexpensive, and portable analytical device for metal analysis.
authors.affiliation: Peter Grünberg Institute, Bioelectronics (PGI-8), Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Benyan
authors.initials: B
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dirk
authors.initials: D
authors.lastname: Mayer
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Krause
authors.forename: Qinghui
authors.initials: Q
authors.lastname: Jin
authors.forename: Jianlong
authors.initials: J
authors.lastname: Zhao
authors.forename: Andreas
authors.initials: A
authors.lastname: Offenhäusser
authors.forename: Yuansen
authors.initials: Y
authors.lastname: Xu
mesh_terms: D004553:Electric Conductivity; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods*; D057230:Limit of Detection; D019216:Metals, Heavy / Q000032:analysis*
chemical_list: D019216:Metals, Heavy