To discover the fate of fluazinam after its application in pepper field, an efficient residual analytical method for determining fluazinam in pepper and soil was developed. The samples were extracted by acetone, clean...To discover the fate of fluazinam after its application in pepper field, an efficient residual analytical method for determining fluazinam in pepper and soil was developed. The samples were extracted by acetone, cleaned up by solid-phase extraction （SPE） florisil cartridge, and determined by gas chromatography with electronic capture detector （ECD）. The recoveries ranged from 80 to 94.6%, with repeatability relative standard deviation ≤9.3% at spiking levels of 0.1-1 mg kg^-1. The residue dynamics of fluazinam in pepper and soil were studied in a field plot. The experiment data showed that the halflives of fluazinam in peppers and soils were 2.5-3.7 days and 1.2-4.2 days, respectively. When the pepper was treated by fluazinam 50% suspension concentrate （SC） at 495 g ha^-1 4 times at 7-day intervals, the fluazinam in pepper on the 7th day after the last application was all below 0.06 mg kg^-1, which was below the maximum residue limit （MRL） fixed in Korea （0.3 mg kg^-1）. It is implied that fluazinam in pepper is nonpersistent. The results suggested that fluazinam 50% SC should be used in a pepper field at most for 4 times, and the pre-harvest interval should be 7 days.展开更多
文摘To discover the fate of fluazinam after its application in pepper field, an efficient residual analytical method for determining fluazinam in pepper and soil was developed. The samples were extracted by acetone, cleaned up by solid-phase extraction （SPE） florisil cartridge, and determined by gas chromatography with electronic capture detector （ECD）. The recoveries ranged from 80 to 94.6%, with repeatability relative standard deviation ≤9.3% at spiking levels of 0.1-1 mg kg^-1. The residue dynamics of fluazinam in pepper and soil were studied in a field plot. The experiment data showed that the halflives of fluazinam in peppers and soils were 2.5-3.7 days and 1.2-4.2 days, respectively. When the pepper was treated by fluazinam 50% suspension concentrate （SC） at 495 g ha^-1 4 times at 7-day intervals, the fluazinam in pepper on the 7th day after the last application was all below 0.06 mg kg^-1, which was below the maximum residue limit （MRL） fixed in Korea （0.3 mg kg^-1）. It is implied that fluazinam in pepper is nonpersistent. The results suggested that fluazinam 50% SC should be used in a pepper field at most for 4 times, and the pre-harvest interval should be 7 days.
