Application of Focused Ultrasound-Assisted Extraction to the Determination of Persistent Organic Pollutants (POPs) in Soil Samples

A simple and rapid focused ultrasound extraction (FU) based method is presented for the determination of persistent organic pollutants (POPs) in soil using a gas chromatography coupled to a mass detector with electron impact ionization. The main experimental parameters affecting the FU step have been optimized by applying a PERMANOVA and PCO analysis allowing us to obtain a maximum amount of information with a minimum number of assays. The limits of detection for POPs fell within the 0.9-6.8 ng/g d.w. interval; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (25 ng/g d.w.) were 75.8 %-110 %, and at high concentrations (75 ng/g d.w.) 82.3 %-109 %; the evaluated precision as RSD% of repeatability and reproducibility were within a range of 0.5 %-11 % and 0.3 %-18 %, respectively.