Occurrence and determination of organic pollutants in aerosol, precipitation, and sediment samples collected at Lake Balaton

Abstract

The results of the determination of different organic pollutants [organic acids, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, volatile hydrocarbons] in aerosols, precipitation, atmosphere, and sediment samples collected at Lake Balaton are presented. Different chromatographic methods were used: capillary zone electrophoresis (CZE) for organic acids, GC–MS for n-alkanes, solid-phase extraction (SPE) and HPLC for PAHs and thermal desorption–GC for BTEX (benzene, toluene, ethylbenzene, m- and p-xylene) compounds. For the determination of the size distribution of organic compounds aerosol was collected by an 8-stage Berner-type low-pressure impactor. Low-molecular mass organic acids were extracted in water in an ultrasonic bath and analysed by CZE. n-Alkanes were extracted by n-hexane, cleaned up on a silica cartridge and analysed by GC–MS. For analysis of PAHs in aerosols, samples were extracted in dichloromethane and acetone, cleaned on a Sep-Pak C 1 8 cartridge and analysed by HPLC–fluorescence detection. Enrichment of PAHs of the precipitation samples was accomplished by SPE on a C 1 8 cartridge. PAHs were eluted with dichloromethane and analysed by HPLC–fluorescence detection. The detection limit was <1 ng l −1 for several PAHs. Well dried and sieved (500-μm sieve) sediment samples were extracted with dichloromethane and acetone. The extracts were cleaned and analysed by HPLC–fluorescence detection. Fourteen PAHs were determined and fluoranthene was found to have the highest concentration at 24 μg kg −1. BTEX compounds were collected by diffusive sampling on Carbopack adsorbent. Samples were analysed by a GC–thermal desorber method and one magnitude higher concentration of volatile compounds was found among the different locations.