title: Determination of chromium(VI) and lead(II) in drinking water by electrokinetic flow analysis system and graphite furnace atomic absorption spectrometry.
abstract: An electrokinetic flow analysis system (EKFA) using an electroosmotic pump (Peo) and a bi-directional electrostacking (BDES) unit is introduced in this paper. Large flow range, moderate carrier pressure, low performance voltage and stable flow rate, especially in mulmin(-1) level, are the main specialties of the Peo. Diethanolamine, 0.5 mM, is selected as its carrier to improve the pump efficiency and stability further. Moreover, BDES, a feasibility investigation for the simultaneous separation and pre-concentration of cations and anions, and graphite furnace atomic absorption spectrometry (GFAAS) determination are presented. The calibration series for both of Cr(VI) and Pb(II) are from 0.2 to 40 mugl(-1) with 10 mul pipette volume and GFAAS determination directly. The detection limit of Cr(VI) and Pb(II) with 10 min BDES is 10 and 13 ngl(-1)(3sigma of blank, n=11), respectively. The recovery of Cr(VI) and Pb(II) is (103-105)+/-1% and (95.9-96.9)+/-1.0% with three independent determinations, respectively. The investigated method is also suitable for the simultaneous separation and pre-concentration of trace cations and anions in low conductivity sample solutions with different detection instruments.
authors.affiliation: Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: Y Z
authors.initials: YZ
authors.lastname: He
authors.forename: W E
authors.initials: WE
authors.lastname: Gan
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: Q S
authors.initials: QS
authors.lastname: Qu
authors.forename: X Q
authors.initials: XQ
authors.lastname: Lin