Determination of hydrocarbons in old creosote contaminated soil using headspace solid phase microextraction and GC-MS

Headspace solid phase microextraction (HS-SPME) has been used together with GC-MS to analyze organic substances directly in a soil, heavily contaminat ed with PAHs/creosote (similar to 300 mg/kg soil), from an old gaswork site in Stockholm, Sweden. The HS-SPME results, both qualitative and quantitati ve, were compared with traditional liquid extraction using ethyl acetate/he xane (20:80). It was shown that the concentrations determined with HS-SPME at 60 degreesC correlated well, for compounds containing up to two and thre e aromatic rings (naphthalenes, acenaphthene, acenaphthylene and fluorenes, while a lower concentration was obtained for phenanthrene, anthracene, flu oranthene and pyrene. The total concentrations for each compound determined with HS-SPME ranged from 2 to 25 mug/g soil. Quantification was done using standard addition of compounds directly to the soil samples. The bioavaila ble fraction of the compounds in the contaminated soil at 20 degreesC was a nalyzed using external calibration by spiking sterile uncontaminated sand ( same texture and particle size as the contaminated soil but without a heavi ly sorbed organic fraction) with hydrocarbon standards in different concent rations. Storage of exposed fibers at 20 degreesC showed that analysis shou ld be done within two days to make qualitative measurements and earlier (as soon as possible) for quantitative determinations. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.