Field-based supercritical fluid extraction of hydrocarbons at industrially contaminated sites.
Examination of organic pollutants in groundwaters should also consider the source of the pollution, which is often a solid matrix such as soil, landfill waste, or sediment. This premise should be viewed alongside the growing trend towards field-based characterisation of contaminated sites for reasons of speed and cost. Field-based methods for the extraction of organic compounds from solid samples are generally cumbersome, time consuming, or inefficient. This paper describes the development of a field-based supercritical fluid extraction (SFE) system for the recovery of organic contaminants (benzene, toluene, ethylbenzene, and xylene and polynuclear aromatic hydrocarbons) from soils. A simple, compact, and robust SFE system has been constructed and was found to offer the same extraction efficiency as a well-established laboratory SFE system. Extraction optimisation was statistically evaluated using a factorial analysis procedure. Under optimised conditions, the device yielded recovery efficiencies of >70% with RSD values of 4% against the standard EPA Soxhlet method, compared with a mean recovery efficiency of 48% for a commercially available field-extraction kit. The device will next be evaluated with real samples prior to field deployment.
Rigou
Peggy
P
Cranfield Centre for Analytical Science, Cranfield University at Silsoe, Silsoe, Bedfordshire, MK45 4DT, UK. rigou.1999@cranfield.ac.uk
Setford
Steven John
SJ
Saini
Selwayan
S
D001554:Benzene / Q000737:chemistry; D001555:Benzene Derivatives / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods; D006838:Hydrocarbons / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis*; D011312:Pressure; D012037:Refuse Disposal; D012989:Soil Pollutants / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014050:Toluene / Q000737:chemistry; D014873:Water Pollutants / Q000302:isolation & purification; D014992:Xylenes / Q000737:chemistry
D001555:Benzene Derivatives; D006838:Hydrocarbons; D007220:Industrial Waste; D012989:Soil Pollutants; D012997:Solvents; D014873:Water Pollutants; D014992:Xylenes; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene