Single-Laboratory Validation Study of Simultaneous Determination Methodfor Five Organochlorine Unstable Pesticides in Agricultural Products by GC-MS/MS

A method was developed for determining five organochlorine unstable pesticides (captan, chlorothalonil, dichlofluanid, folpet, and tolylfluanid) in agricultural products using GC-MS/MS. To prevent pesticide degradation, the food sample was maintained at -20℃ until the initiation of the extraction process. The sample underwent homogenization with acetonitrile and salting out using anhydrous magnesium sulfate and sodium chloride in the presence of citrate salts. Cleanup was executed using Graphite Carbon and C18 SPE cartridges. The validation of this method was tested on five agricultural products at two concentrations (0.01 and 0.1 μg/g). The recovery rates varied between 86.7% and 96.1%. RSDs for repeatability were less than 15.2% and 8.8%, while the RSDs for within-laboratory reproducibility were under 19.9% and 12.7%. These results meet the criteria established by the validation guidelines in Japan.