Abstract
An analytical method for chlorfluazuron (CFA) in feed by HPLC was established. Water was added to a sample, and CFA was extracted with acetonitrile. The extract was cleaned up on a porous diatomite cartridge, followed by a Florisil column and a silica cartridge. The CFA was determined by HPLC on an ODS column of Mightysil RP18 (4.6mm i. d.×250mm) with a UV detector (260nm). The recovery test was conducted with 3 kinds of feed spiked with CFA at levels of 0.02-2.0ppm. The mean recovery values were in the range of 78.7-95.7%, and the relative standard deviations of repeatability (RSDr) were within 14.1%. A collaborative study (7 laboratories) was conducted with mixed feed spiked with CFA at the level of 1.0ppm. The mean recovery was 87.7%, and the relative standard deviation of reproducibility (RSDR) was 3.7%. The detection limit was 0.02ppm in a sample.
