抽象的

Determination of diniconazole fungicide residues in grapes and zucchini by capillary gas chromatography

Hayam M.Lotfy, Abdel-Aziz A.Abdel-Aleem, Hany H.Monir

A sensitive gas chromatographic method using an electron-capture detector (ECD) has been developed for the determination of diniconazole fungicide residues in grapes and zucchini. The developed method consists of extraction with ethyl acetate, and column chromatographic clean-up, followed by capillary gas chromatographic determination. The recoveries of diniconazole were greater than 90% for both plant samples. The limit of determination of the method was 0.0001 ppm. The method was applied to determine residues and the rate of disappearance of diniconazole fromgrapes and zucchini [open field treatment, 35 cc of Sumi-eight 5%EC (emulsifiable concentrate) for 100 L of water]. The fungicide incorporated into the plants decreased rapidly with a half-life time around 6 days in grapes and 2 days for zucchini. It is recommended not to apply diniconazole on grapes after maturation stage No residues could be detected in zucchini 16 days after field application. Hence, the plant could be used safely after that period of time. Four market samples were chosen fromdifferent regions fromA.R.E. and all of them showed no residues of diniconazole.