Effect of Storage on the Recovery of Different Types of Pesticides Using a Solid-phase Extraction Method

Abstract

Recoveries of different pesticide groups after storage either on C ₁₈ cartridges or as dried residues from organic solutions, and their analysis by gas chromatography with electron capture and flame photometric detection, were studied. Two storage temperatures, 4 and -18 °C, and three storage periods, 3, 7 and 30 d, were considered. The effect of storage temperature and storage time on the recovery of 27 pesticides in water was investigated. In general, the pesticide recoveries were ≥70% after 30 d of storage at -18 °C on C ₁₈ cartridges. Exceptions included captan and folpet. The storage of the dried residues generally did not affect the pesticide recovery when kept at -18 °C for up to 30 d.