LAUSR

Abstract The aim of the presented study was to use a recently developed CGU-ACTJU-IC system for on-line determination of dicarboxylic acids (DCAs) in aerosols over short time periods involving aerosol sampling into deionized water using a Condensation Growth Unit – Aerosol Counterflow Two-Jets Unit (CGU-ACTJU) sampler, quantitative preconcentration of analytes and determination by ion chromatography (IC). The parameters of automated on-line preconcentration method, using two parallel preconcentration columns and piston pump, were optimized. Limits of detection of studied DCAs, i.e., oxalic, malonic, succinic, glutaric/adipic, pimelic, azelaic and maleic acid, were determined to 0.27, 0.92, 1.74, 0.82, 1.17, 1.41 and 0.48 ng m−3, respectively. The optimized method was used for the analysis of DCAs in urban aerosol in Brno in two campaigns: from 5th to 9th December 2016 and from 12th to 21st July 2017. The results obtained by the developed method were compared with two reference methods including sampling of aerosols on filters and subsequent analysis of DCAs by gas chromatography with mass spectrometry (GC/MS) or IC. The presented study describes an alternative on-line method, compared to filter sampling, for monitoring of DCAs in atmospheric aerosols, allowing measurement with 1-h time resolution.