Simultaneous Analysis of Seven Non-authorized Pesticides Residue in Cucumber Using Spiked Calibration Curve by GC/ECD

Lack of farmers’ knowledge, illegal production and import, and economical situation are the main reasons for non-authorized usage. In this study, one of the major center of cucumber cultivation at south west of Iran, Darreh shahr City in Ilam Province were studied for non-authorized pesticides usage, which health authorities and national standard organization do not recommend.
A reliable, rapid and accurate method based on spiked calibration curves and modified QuEChERS sample preparation was developed for determination of 7 non-authorized pesticides. During 2014 fifty cucumber samples were collected and analyzed by gas chromatography Electron Capture Detector (GC/ECD). For overcoming matrix effects, calibration curve was prepared by spiked samples.
Method was validated with related parameters. The recovery of pesticides at five concentration levels (n=3) was in the range of 81.02-91.66%. The method was proved repeatable with RSD lower than 20%. The limits of quantification for all pesticides were 10 ng/g.
There are some pesticides which are legally used with identified MRL in cucumber, but for better protection farmers used another pesticides which are not permitted by health authorities, consequently are harmful for consumers. Related fields inspections showed that some specific pesticides were applied for this purpose, such as α-endosulfan, β-endosulfan, endosulfan sulfate, α-HCH, β-HCH, γ-HCH and phosalone that was found in three cucumber samples (6%).