Chemical characterisation of adsorbable organic halogens (AOX) in precipitation
1995; Springer Nature (Netherlands); Linguagem: Inglês
10.1007/978-94-011-0061-8_9
ISSN1383-8598
AutoresKrzysztof Łaniewski, Hans Borén, Anders Grimvall, Susanne Jonsson, Lena von Sydow,
Tópico(s)Water Quality Monitoring and Analysis
ResumoThe average concentration of AOX (adsorbable organic halogens) in precipitation was found to vary from 2 – 3 µg Cl/L at remote sites in northern Sweden and Finland to approximately 10 µg Cl/L further to the south in the Baltic Sea region. By using different methods to concentrate and fractionate dissolved organic substances, this group of substances was characterised with respect to volatility, polarity and occurrence of specific organochlorine and organobromine compounds. Aqueous phases were analysed for the group parameters AOX and TOC (total organic carbon). Organic phases were analysed for the total amount of organohalogens and by gas Chromatographic procedures employing different detectors, mainly the element-specific atomic emission detector (AED) and mass spectrometry (MS). The results obtained showed that AOX in precipitation are mainly non-volatile. Furthermore, neutral compounds were found to dominate, and precipitation AOX thereby differ from surface water AOX. A substantial part of the AOX in precipitation were efficiently adsorbed to the non-ionic adsorbent XAD-8 and almost quantitatively desorbed by organic solvents. However, the gas Chromatographic analyses of different extracts of organic substances showed that chloroacetic acids were the only specific compounds that contributed significantly to AOX in precipitation. A few other organochlorine compounds, probably released from local sources, were present in ppt concentrations.
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