Removal effects of six kinds of cleaning methods on strobilurin pesticide residues in fruits and vegetables

The residues of pyraclostrobin and azoxystrobin on cucumbers and strawberries were detected by QuEChERS-LC-MS/MS after washing polluted samples with tap water,cleaning salt for fruits and vegetables,milk powder,Biya enzyme vegetable quick lotion,detergent and washing machine. The results showed that soaking with milk powder solution was demonstrated to be more effective(reduction rates of 60.01%~69.91%)than treating with detergent and tap water significantly(p<0.05). Cleaning with machine decreased the residues of 59.55% to 64.87% on strawberries and 40.29% to 48.40% on cucumbers. There was no significant difference of declining pesticide residues on both strawberries and cucumbers.Between cleaning salt(reduction rates of 39.91%~64.50%)and Biya enzyme(reduction rates of 39.63%~65.35%)The reduction rates of detergent on samples were 32.50%~52.02%. Among these washing methods,washing with tap water was proved to be the least effective since it only reduced the residues by 22.45%~44.41%,which was significantly lower than that of milk powder,cleaning salt and Biya enzyme(p<0.05). It was concluded that all these washing methods could eliminate pesticide residues on fruits and vegetables. Rinsing with milk powder solution was the most effective treatment and soaking with tap water was the worst one.