EFFECT OF STORAGE ON THE RECOVERY OF DIFFERENT TYPES OF PESTICIDES USING A SOLID-PHASE EXTRACTION METHOD

Recoveries of different pesticide groups after storage either on C-18 cartridges or as dried residues from organic solutions, and their anal ysis by gas chromatography with electron capture and flame photometric detection, were studied. Two storage temperatures, 4 and -18 degrees C, andthree storage periods, 3, 7 and 30 d, were considered. The effec t of storage temperature and storage time on the recovery of 27 pestic ides in water was investigated. In general, the pesticide recoveries w ere greater than or equal to 70% after 30 d of storage at -18 degrees C on C-18 cartridges, Exceptions included captan and folpet. The stora ge of the dried residues generally did not affect the pesticide recove ry when kept at -18 degrees C for up to 30 d.