Analysis of hydrocarbon-contaminated soil by thermal extraction - Gas chromatography

The combination of thermal extraction and gas chromatography (ThermEx-GC) was used to analyze hydrocarbons in creosote- and petroleum-contaminated soil. By volatilizing target compounds from the soil into the carrier gas of a gas chromatograph, the method provides direct and rapid analysis of contaminated soils. The detectability and reproducibility of the analysis were determined using a mixture of anthracene and phenanthrene loaded into a clean soil. Analyses of creosote and hydrocarbon-laden soils from a contaminated site were comparable to data from Soxhlet extraction with methylene chloride followed by GC-FID. The detection of hydrocarbons from the ThermEx was dependent on both the size of the soil sample and the concentration of hydrocarbons on the soil. Procedures were developed for calibrating the ThermEx-GC for the presence of non-distillable hydrocarbons and for interferences from the soil matrix, but non-linearities in the response limit the method to monitoring of remediation processes.