Cypermethrin Residues in Fresh Vegetables: Detection by HPLC and LC- ESIMS and their Effect on Antioxidant Activity

Cypermethrin, a synthetic pyrethroid, is used as pesticide in large-scale commercial agricultural applications as well as in consumer products for domestic purposes. Fresh vegetables are of the focal points of this study, since they are a significant source of phenolic antioxidants. In this study, we applied the HPLC and LC-ESIMS techniques to detect cypermethrin residues in five fresh vegetables, when applicable with illegal doses by some farmers. For this purpose, samples of fresh bio-vegetables were bought and divided into three groups, one of which was treated with an illegal dose of cypermethrin. All samples (blank, treated with legal and illegal doses) were then cut into small pieces, frozen and lyophilized. Freeze- dried samples were extracted with ethyl acetate, filtered and evaporated till dryness. Interestingly, comparison of antioxidant activity of organic fennel, cabbage, and celery samples which were not exposed to pesticide treatment with treated samples (propylgallate positive control having 100% antioxidant activity) showing a reduction of antioxidant activity for the treated samples which was very obvious in the cabbage sample but slighter in fennel and celery samples. These results indicate a lower nutritional quality of the treated vegetables with illegal doses.