Appraisal of "classic” and "novel” extraction procedure efficiencies for the isolation of polycyclic aromatic hydrocarbons and their derivatives from biotic matrices

In this study the extraction efficiency of pressurized liquid extraction (PLE), employing different extraction solvent mixtures under different extraction conditions, was compared with extraction efficiencies of commonly used procedures, Soxhlet extraction and extraction enhanced by sonication. Spruce needles and fish tissue were selected as test samples. Purification of obtained extracts was carried out by gel permeation chromatography (GPC) employing gel Bio-Beads S-X3. Identification and quantitation of target PAHs was performed by high-performance liquid chromatography with fluorescence detection (HPLC–FLD). Within optimisation of PLE conditions, temperature of extraction, type of solvent, duration and number of static cycles as well as the influence of sample pre-treatment (drying, homogenisation, etc.) were tested. Comparison of the extraction efficiency of PLE with the efficiencies of the other techniques was done under the optimised conditions, i.e. sample slurry obtained by desiccation with anhydrous sodium sulphate, extracted at 100 °C in 1 cycle lasting 5 min. Hexane:acetone (1:1, v/v) was chosen as the most suitable extraction solvent for isolation of analytes from test samples. Comparison of mentioned isolation techniques with respect to the amount of co-extracts, procedure blank levels and time and solvent volume demands was also done.