Naslov
Partitioning of selected environmental pollutants into organic matter as determined by solid-phase microextraction

Autori
Prosen, Helena ; Fingler, Sanja ; Mandelj, Lucija ; Zupančič-Kralj Lucija ; Drevenkar, Vlasta

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
10th International Symposium on Separation Sciences "New Achievements in Chromatography", Book of Abstracts / Šegudović, Nikola - Zagreb : Hrvatsko društvo kemijskih inženjera i tehnologa (HDKI), 2004

Skup
10th International Symposium on Separation Sciences "New Achievements in Chromatography"

Mjesto i datum
Opatija, Hrvatska, 12.10.2004. - 15.10.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Dissolved organic matter; sorption; partitioning; PCBs; organochlorine insecticides; triazine herbicides; amide herbicides; SPME

Sažetak
Partitioning of organic pollutants into the organic matter (OM) in soil (SOM) and surface water (dissolved organic matter - DOM) is a well-established fact, although the mechanisms by which it occurs are not always well understood [1]. In order to evaluate the extent of partitioning, either free or bound amount of compounds should be measured. Although there is an ongoing discussion of the (dis)advantages of different methods for the measurement of the free concentrations [2-4], negligible depletion solid-phase microextraction (nd-SPME) seems to be a reliable choice [3, 5]. Analysis is usually accomplished by gas chromatography (GC) [6]. Our aim in the present study was to evaluate the partitioning of some selected environmental pollutants (PCBs, organochlorine insecticides, triazine and amide herbicides) into dissolved (DOM) and soil organic matter (SOM) by measuring their free concentrations by nd-SPME. Analysis was performed by GC with either ECD or NPD. Compounds were chosen regarding their polarity to cover a wide range of log Kow (2.2-7.6). Aqueous solution of the chosen pollutants was mixed with two soils with different SOM content or with Florisil (magnesium silicate) as an inorganic adsorbent to match the silicates in the soil. Another set of partitioning experiments was performed in the aqueous solution of pollutants and commercial humic acids (HAs), the latter matching in concentration dissolved organic carbon of soil suspensions. Two different types of partitioning behaviour were observed in these experiments. Compounds with log Kow > 5 partitioned almost instantly into DOM fraction. The remaining free fraction was 10-50 % of the initial amount, depending on the compound and DOM concentration and remained almost constant after initial partitioning. The behaviour of these compounds in soil suspensions was similar, but strong sorption on Florisil was also noticed, matching the sorption/partitioning on soil. For PCB-15 with log Kow  5, free concentration in HA solutions decreased only after several hours of contact time. Slower sorption/partitioning was observed in soil and Florisil suspensions as well, but free concentrations in both did not differ significantly. For compounds with log Kow 2-4, free concentrations in HA solutions did not change over time, remaining at 100 % of the initial concentration or even higher, which can be attributed to the "shuttle effect" of humic substances [3]. In soil suspensions, however, some sorption/partitioning was observed over time, but sorption was at least matching or even stronger on Florisil. The latter indicates that sorption onto silicates might be the prevailing mechanism for binding of the more polar compounds in the soil. [1] De Paolis, F., Kukkonen, J., Chemosphere 34 (1997) 1693-1704. [2] Lee, S., Gan, J., Liu, W.P., Anderson, M.A., Environ. Sci. Technol. 37 (2003) 5597-5602. [3] Kopinke. F.D., Poerschmann, J., Georgi, A., in Applications of Solid Phase Microextraction, Ed. J. Pawliszyn, RSC, Cambridge, UK, 1999, pp. 111-128. [4] Mott, H.V., Adv. Environ. Res. 6 (2002) 577-593. [5] Heringa, M.B., Hermens, J.L.M., TrAC 22 (2003) 575-587. [6] Prosen, H., Troha, A., Zupančič-Kralj, L., Acta Chim. Slov. 49 (2002) 561-573.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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