Fate of hexaconazole residues in tea and its behavior during brewing process.

Dissipation behavior of hexaconazole, an effective fungicide, recently introduced in India for controlling blister blight, applied under field condition on tea crop in wet and dry seasons was studied in green leaves, made tea, tea infusion and spent leaves. A simple, rapid analytical procedure for the determination and quantification of hexaconazole in these samples (matrices) was developed using gas chromatography with nitrogen phosphorus detector. Degradation rate in both the seasons followed first order kinetics with half lives in green leave in the range of 1.56–1.67 and 1.80–1.87 days and in made tea half lives were 1.76–1.82 and 1.84–1.91 days for wet and dry season respectively. The transfer of hexaconazole residue to infusion was found to range from a maximum of 8.88% of the residue present in made tea during wet season and to 8.84% during the dry seasons. The residue remaining in spent leaves from made tea was in the range of 46.76–76.12% during the wet season and between 51.82 and 76.96% during the dry season. Balance amount seems to be degraded during the preparation of infusion. A waiting period of 7 days after pesticide application at recommended dose for tea plucking may be suggested from point of hazards due to residues