Determination of 4'-deoxy-4'-(epimethylamino)avermectin B1 benzoate (MK 0244) and its delta 8,9-isomer in celery and lettuce by HPLC with fluorescence detection

Autor: Teresa A. Wehner, Patricia C. Tway, Richard S. Egan, Sunil V. Prabhu
Rok vydání: 1991
Předmět:
Zdroj: Journal of Agricultural and Food Chemistry. 39:2226-2230
ISSN: 1520-5118
0021-8561
DOI: 10.1021/jf00012a025
Popis: An analytical method has been developed for the extraction, derivatization, and fluorescence HPLC determination of MK-0244 [4"-deoxy-4"-(epimethylamino)avermectin B1 benzoate salt] and its delta 8,9-isomer from lettuce and celery at trace (parts per billion) levels. MK-0244 and its delta 8,9-isomer are extracted with methanol, and the extract is cleaned up on a reverse-phase C8 cartridge followed by a liquid-liquid extraction with ethyl acetate before passing through a propyl sulfonyl cation-exchange cartridge. MK-0244 and its delta 8,9-isomer are then derivatized with trifluoroacetic anhydride/1-methylimidazole/acetonitrile reagent system to form a fluorescent derivative which is separated on a reverse-phase HPLC system and detected with a fluorescence detector. The average recoveries were 95 +/- 10% for celery and 96 +/- 8% for lettuce. For both lettuce and celery matrix, concentrations as low as 2 ppb (S/N = 10) can be detected in a 10-g sample. This method was used to determine the MK-0244 levels in samples from a lettuce field trial.
Databáze: OpenAIRE