Microwave-assisted solvent extraction — a new method for isolation of polynuclear aromatic hydrocarbons from plants

The efficiencies of polynuclear aromatic hydrocarbons (PAHs) transfer into various solvents from pollen and spruce needles by two alternative extraction techniques — sonication and a microwave enhanced process — were compared. The effects of extraction mixture composition, temperature, time and number of repeated extractions on the recoveries were studied. Microwave extraction — realised at 140°C for 20 min with n-hexane–acetone (3:2, v/v) as the extraction solvent — was identified as the most effective extraction procedure for isolation of PAHs from biotic matrices (pollen and spruce needles). Gel permeation chromatography on Bio-Beads S-X3 with chloroform as a mobile phase was used for clean-up of extracts. HPLC with programmable fluorescence detection was employed for identification and quantification of analytes.