Transfer of difenoconazole and azoxystrobin residues from chrysanthemum flower tea to its infusion

Investigations of the transfer of pesticide residues from tea to its infusion can be important in the assessment of the possible health benefits of tea consumption. In this work the transfer of difenoconazole and azoxystrobin residues from chrysanthemum tea to its infusion was investigated at different water temperatures, infusion intervals and times. The transfer percentages were in the range of 18.7-51.6% for difenoconazole and of 38.1-71.2% for azoxystrobin, and increased considerably with longer infusion intervals. The results indicated that azoxystrobin with a lower octanol-water partition coefficient of 2.5, showed a higher transfer than that of difenoconazole with a relatively high octanol-water partition coefficient of 4.4. Water temperature had no significant effect on the transfer of the two residues, and no obvious loss of difenoconazole and azoxystrobin occurred during the infusion process. The concentrations in the infusions decreased gradually from 0.67 to 0.30 mu gkg(-1) for difenoconazole and from 2.3 to 0.46 mu gkg(-1) for azoxystrobin after five infusions. To assess the potential health risk, the values of estimate expose risk were calculated to be 0.016 for difenoconazole and 0.0022 for azoxystrobin, meaning the daily residue intake of the two analytes from chrysanthemum tea was safe. This research may help assure food safety and identify the potential exposure risks from pesticides in chrysanthemum that may be health concerns.