Investigation of the effects of household processing on the reduction rate of chlorpyrifos, metalaxyl and diazinon residues in orange fruit

The effect of the household processing on the reduction rate of chlorpyrifos, metalaxyl and diazinon residues in contaminated oranges has been investigated and the processing factors were determined. The evaluation included validation parameters, matrix effect (ME %), reduction behavior and processing factors (PFs). Validation parameters were successfully applied; the three pesticides showed satisfactory recovery (70–120%) and precision (relative standard deviation - RSD<20%); they also exhibited no matrix effect. The most effective process in the pesticide residues reduction was juicing, followed by pulping while the washing process was less efficient in removing all pesticide residues; sonication showed a high reduction rate with both chlorpyrifos and diazinon. The processing factors (PFs) were generally less than one which indicates that all processes can reduce pesticide residues in oranges. The results could guide the safe and reasonable use of chlorpyrifos, diazinon, and metalaxyl. These processes contribute substantially to reduce consumer exposure to pesticide residues in oranges.