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 extracti on techniques - sonication and a microwave enhanced process - were compared . The effects of extraction mixture composition, temperature, time and numb er of repeated extractions on the recoveries were studied. Microwave extrac tion - realised at 140 degrees 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 ne edles). Gel permeation chromatography on Bio-Beads S-X3 with chloroform as a mobile phase was used for clean-up of extracts. HPLC with programmable fl uorescence detection was employed for identification and quantification of analytes. (C) 1998 Elsevier Science B.V. All rights reserved.