SAMPLE HANDLING IN ANALYSIS OF PESTICIDE-RESIDUES IN FOODSTUFFS

To get a good precision of data generated determination of pesticide r esidues in foodstuffs, an efficient clean-up of primary extracts has t o be carried out. In our experiments, automated (ASPEC XL. Gilson, Fra nce) gel permeation chromatography was used for purification of ethyl acetate extracts of spinach, carrots and apples which were spiked by 4 2 pesticides (0.05-0.4 mg.kg(-1)) currently detected in respective cro ps. The advantages of rigid Pl gel over soft BioBeads SX-3 were demons trated. In system consisting of a Pl gel column (10 mm, 600 x 0.75 mm) with ethyl acetate-cyclohexane (1:1, v/v) as a mobile phase, good eff iciency and high repeatability of clean-up step were obtained, the rec overies of pesticides ranging from 70 to 105 %.