Jump to main content
Jump to site search

Issue 11, 2006
Previous Article Next Article

Analysis of anions in ambient aerosols by microchip capillary electrophoresis

Author affiliations


We describe a microchip capillary electrophoresis method for the analysis of nitrate and sulfate in ambient aerosols. Investigating the chemical composition of ambient aerosol particles is essential for understanding their sources and effects. Significant progress has been made towards developing mass spectrometry-based instrumentation for rapid qualitative analysis of aerosols. Alternative methods for rapid quantification of selected high abundance compounds are needed to augment the capacity for widespread routine analysis. Such methods could provide much higher temporal and spatial resolution than can be achieved currently. Inorganic anions comprise a large percentage of particulate mass, with nitrate and sulfate among the most abundant species. While ion chromatography has proven very useful for analyzing extracts of time-integrated ambient aerosol samples collected on filters and for semi-continuous, on-line particle composition measurements, there is a growing need for development of new compact, inexpensive approaches to routine on-line aerosol ion analysis for deployment in spatially dense, atmospheric measurement networks. Microchip capillary electrophoresis provides the necessary speed and portability to address this need. In this report, on-column contact conductivity detection is used with hydrodynamic injection to create a simple microchip instrument for analysis of nitrate and sulfate. On-column contact conductivity detection was achieved using a Pd decoupler placed upstream from the working electrodes. Microchips containing two Au or Pd working electrodes showed a good linear range (5–500 µM) and low limits-of-detection for sulfate and nitrate, with Au providing the lowest detection limits (1 µM) for both ions. The completed microchip system was used to analyze ambient aerosol filter samples. Nitrate and sulfate concentrations measured by the microchip matched the concentrations measured by ion chromatography.

Graphical abstract: Analysis of anions in ambient aerosols by microchip capillary electrophoresis

Back to tab navigation

Article information

23 Jun 2006
21 Aug 2006
First published
15 Sep 2006

Analyst, 2006,131, 1226-1231
Article type

Analysis of anions in ambient aerosols by microchip capillary electrophoresis

Y. Liu, D. A. MacDonald, X. Yu, S. V. Hering, J. L. Collett, Jr. and C. S. Henry, Analyst, 2006, 131, 1226
DOI: 10.1039/B608945C

Social activity

Search articles by author