Comparison of Modern Extraction Techniques in Analysis of Soil Contaminated with Fuel and Crude Oil Spills

Abstract

Supercritical fluid extraction (SFE) with CO₂ and pressurised fluid extraction (PFE) have been investigated for assays of soil samples contaminated with crude oil and compared with reference Soxhlet extractions using 1,1,2‐trichlorotrifluoroethane (Ledon 113). Quantitative extraction of total petroleum hydrocarbons (TPH) by SFE was accomplished in 30 min at a pressure of 40 MPa and temperature of 100°C by using pure CO₂. For the PFE Ledon 113 as extractant, 100°C, 10 MPa, and two 5 min static steps were found as optimal conditions for quantitative extraction of petroleum hydrocarbons. To determine TPH in the extracts, Fourier transformation infrared spectrometry was used. Capillary gas chromatography with flame ionization detection provided information allowing one to differentiate the source of contamination of soil in the vicinity of an oil exploitation site.

Keywords:

• Supercritical fluid extraction
• Pressurised fluid extraction
• Total petroleum hydrocarbons

Acknowledgments

All experiments were performed thanks to financial support from the Ministry of Education, Youth and Sports of the Czech Republic (Project MM 253100002), and from the Grant Agency of the Czech Republic (Project 203/02/0023).