An aliquot (10g) of previously homogenized sample was weighed into a centrifuge tube and 10mL of extraction solvent was added. the mixture was homogenized for 1.5 min using an Ultra Turrax T25 mixer at5000rpm.After centrifugation,5mL of the organic layer was carefully evaporated to dryness with a rotary evaporator at 40°C. The residue was reconstituted with 1mL of cyclohexane and
tranasferred to GG vials for chromatographic injection.