Determination of chlorophenols in soils using accelerated solvent extraction combined with solid-phase microextraction

A method for the determination of chlorophenols in soil samples using accelerated solvent extraction (ASE) with water as the solvent combined with solid-phase microextraction (SPME) and GC/MS has been developed. Important ASE parameters, such as extraction temperature and time, were optimized using a spiked wetland soil. The effect of small amounts of organic modifiers on the extraction yields was studied. An extraction temperature of 125 degrees C and 10 min extractions performed three times proved optimal. Two ASE-SPME procedures without and with an organic modifier (5% acetonitrile) were evaluated with respect to precision and detection limits (LOD). The reproducibility of replicate water extractions/SPME determinations (n = 6) was in the range 7-20% relative standard deviation for the nine chlorophenols investigated. LOD values in the low-ppb range were achieved for all chlorophenols. The ASE-SPME procedure presented here was applied to the determination of chlorophenols in soil samples taken from contaminated areas near Bitterfeld, Germany.