摘要：This study was performed to examine the effect of ozonation treatment at different ozone concentrations (0.5, 2 and 5) ppm for different periods of time (5, 10 and 15) minutes on reduction percentage of spiked chlorfenapyr of (2, 6 and 10) ppm on lettuce leaves using gas chromatography equipped with micro electron capture detector. The results showed that ozonation treatment at 0.5, 2 and 10 ppm significantly reduced the spiked chlorfenapyr concentration on lettuce, after 15 minutes of ozone treatment the concentration of chlorfenapyr did not reach the allowed maximum residues limits in European regulations (0.01) ppm. The maximum reduction percentages after 15 min of ozone treatment at 0.5 ppm were 85.81, 88.47 and 91.21% for spiked concentrations of chlorfenapyr at 2, 6 and 10 ppm, respectively. On the other hand, the maximum reduction percentages after ozone treatment for 15 min at 2 ppm were 88.94, 93.25 and 94.77 % for spiked concentration of chlorfenapyrat 2, 6 and 10 ppm, respectively. At last the maximum reduction percentages for 15 min at 5 ppm ozone concentration were 92.25, 96.33 and 97.15 % for spiked concentrations of chlorfenapyrat 2, 6 and 10 ppm, respectively. Meanwhile, the reduction percentages after soaking with tap water for 15 min were 7.20,10.137 and 2.02 % for2, 6 and 10 ppm spiked chlorfenapyr concentrations on lettuce fruits. It was concluded from this research that ozone treatment has a significant effect on chlorfenapyr spiked concentrations and it could be used as a method for reduction of this pesticide residues in fruits and vegetables, but it need more than 15 min of ozone treatment to reduce its concentration below the European maximum residue limit. Ozone affected the pesticides residues concentration in a concentration-time dependent manner.
