engleski

Distribution of polycyclic aromatic hydrocarbons (PAH) in Croatian soils: ossible impact of war activities

A method for the determination of 16 polycyclic aromatic hydrocarbons (PAH) in soil and sediment samples has been validated and applied for a survey of PAH in war-affected areas of Croatia. Air-dried samples were extracted by accelerated solvent extraction (ASE) using a mixture of dichloromethane and cyclohexane as an extraction solvent. The extracts were evaporated to dryness, re-dissolved in n-hexane and subsequently fractionated on a silica gel column. The fraction, eluted with 30% of dichloromethane in n-hexane, was collected for the analysis of PAH. Quantitative analyses of the collected fractions were performed using gas chromatography coupled to ion-trap mass spectrometry (GC/MS), operated in full scan mode. This allowed both simultaneous qualitative analysis of the extracts for non-target compounds and quantitative determination of the selected non-substituted PAH. Detection limits based on 7 g-samples ranged from 3-6 ng/g. The soil samples were collected in the period from 2002 and 2005 and covered about 160 locations in different areas, affected by the 1991-1995 war in Croatia. The total PAH concentrations in analysed samples varied in a very wide range from 10 ng/g to 1 mg/g, however majority of samples contained total PAH in concentrations between 100 and 1000 ng/g, reflecting typical values of moderately polluted top-soils. The most abundant individual PAH in the samples were fluoranthene, pyrene and benzo(b)fluoranthene.

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