HR: 0800h
AN: A41A-0030    [Abstracts]
TI: Aerosol Anion Analysis Using PDMS Based Microchip Capillary Electrophoresis
AU: * Yu, X
EM: xiaoying@lamar.colostate.edu
AF: Colorado State University, Dept. of Atmospheric Science Campus 1371 Delivery, Fort Collins, CO 80523-1371 United States
AU: Liu, Y
EM: yanliu@lamar.colostate.edu
AF: Colorado State University, Dept. of Chemistry Campus 1872 Delivery, Fort Collins, CO 80523-1872 United States
AU: MacDonald, D
EM: David.MacDonald@colostate.edu
AF: Colorado State University, Dept. of Chemistry Campus 1872 Delivery, Fort Collins, CO 80523-1872 United States
AU: Hering, S V
EM: susanne@aerosol.us
AF: Aerosol Dynamics Inc., 2329 Fourth Street, Berkeley, CA 94710 United States
AU: Henry, C S
EM: cshenry@lamar.colostate.edu
AF: Colorado State University, Dept. of Chemistry Campus 1872 Delivery, Fort Collins, CO 80523-1872 United States
AU: Collett, J L
EM: collett@lamar.colostate.edu
AF: Colorado State University, Dept. of Atmospheric Science Campus 1371 Delivery, Fort Collins, CO 80523-1371 United States
AB: We developed a lab-on-a-chip capillary electrophoresis (LOC-CE) system to analyze important inorganic ions such as nitrate and sulfate, found in ambient aerosols. Capillary electrophoresis (CE) is a simple technique for separation and measurement of analytes in solution. Ions are separated, depending on their size and charge, in an electrolyte filled capillary under an electric gradient field. Miniaturized CE systems offer enhanced separation speed while maintaining high separation efficiency and permit multi-channel analysis, presenting great potential for building sensitive, portable, and economical instruments for environmental analysis. The microchip CE system created in our laboratory is simple and effective. The chip is made of PDMS (polydimethylsiloxane). The separation channel is approximately 4.0 cm long and coated with polybrene to modify electroosmotic flow. The electrolyte is composed of 10 mM formic acid adjusted to pH 3. Conductivity detection is used to quantify concentrations of target ions. Sample analysis times are approximately 2 minutes. System calibration was established using standard solutions and detection limits of sulfate and nitrate were determined. Day-to-day and chip-to-chip reproducibility was also evaluated. We applied the microchip CE system to analyze several winter aerosol samples collected in Bondville, IL. Aqueous extracts of these aerosol samples were also analyzed by conventional ion chromatography. Quantifications of sulfate by the CE and IC show good agreement. Additional testing revealed the capability of the microchip CE system to successfully analyze aerosol microdeposits made by impaction of the droplet stream emerging from a water condensation particle collector (WCPC). This is a key step in creating an integrated, on-line particle collection and analysis system.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0365 Troposphere--composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting