2.4. Extraction procedure
The honey samples were thoroughly homogenized and approximately
5 g of the homogenate was weight into PFTE tube (50 mL)
containing 10 mL deionized water and 10 mL acetonitrile acidified
with acetic acid. The content was shaken manually and 4.0 g anhydrous
magnesium sulphate, 1.0 g sodium chloride, 1.0 g sodium
citrate and 0.5 g sodium hydrogen citrate sesquihydrate were
added. The mixture was immediately hand-shaken for 1 min and
subsequently centrifuged at 4000 RPM for 3 min. Thereafter,
1 mL of the upper clear solution was transferred into 15 mL polyethylene
tube containing 25 mg PSA sorbent and 150 mg anhydrous
magnesium sulphate. The tube was shaken vigorously for
1 min and centrifuged for 1 min at 5000 RPM. Finally, 0.5 mL of
the supernatant was taken in a glass vial, evaporated to dryness
and redissolved in 0.5 mL n-hexane for GC-lECD analysis.