title: Prediction of [3-(14)C]phenyldodecane biodegradation in cable insulating oil-spiked soil using selected extraction techniques.
abstract: This study investigated the use of an aqueous hydroxypropyl-beta-cyclodextrin (HPCD) shake extraction in predicting microbial mineralisation and total loss of [3-(14)C]phenyldodecane associated activity in soils spiked with cable insulating oil; phenyldodecane represents a major constituent of cable insulating oil. Direct comparisons were made between freshly spiked and aged soils, and following composting. Soil was spiked with [3-(14)C]phenyldodecane (10mg kg(-1)) and stored in microcosms and aged for 1, 23, 44, 65, 90 and 153 d. At each sample time point, a variety of analyses were performed to assess the relationship between chemical and biological techniques in determining mineralisation and loss of (14)C-activity in soils under composting and non-composting conditions. Methods included determination of total (14)C-activity remaining, dichloromethane (DCM) and HPCD extractions. Mineralisation assays were also carried out to quantify the fraction of (14)C-phenyldodecane associated activity available for degradation in the soil at each time point. DCM and HPCD extractability were compared to contaminant mineralisation and to total loss of (14)C-phenyldodecane associated activity from the microcosms, after 153 d incubation. Poor relationships were found between (i) the amount of (14)C-activity mineralised and the fraction removed from the soils using DCM extraction and (ii) DCM extraction and total loss of [(14)C]phenyldodecane associated activity from the soil systems. Good relationships were observed between (i) the amount of (14)C-activity mineralised and the fraction removed from the soils using the HPCD extraction and (ii) HPCD extraction and total loss of [(14)C]phenyldodecane associated activity from the soil systems. The results of this study indicate that an aqueous HPCD extraction may be a useful tool in assessing the microbial availability of phenyldodecane in freshly and aged spiked soils.
authors.affiliation: Department of Environmental Science, Institute of Environmental and Natural Science, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Nadia M
authors.initials: NM
authors.lastname: Dew
authors.forename: Graeme I
authors.initials: GI
authors.lastname: Paton
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Semple
mesh_terms: D000473:Alkanes; D001673:Biodegradation, Environmental; D002273:Carcinogens; D004784:Environmental Monitoring / Q000379:methods; D004787:Environmental Pollution; D009821:Oils; D012988:Soil Microbiology; D012989:Soil Pollutants
chemical_list: D000473:Alkanes; D002273:Carcinogens; D009821:Oils; D012989:Soil Pollutants; C007548:n-dodecane