AGRO 55 |
| Brodifacoum(3-[3-(4'-Bromo[1,1'-biphenyl]-4-yl)1,2,3,4-tetrahydro-1- naphtalenyl]-4-hydroxy-2H-1-benzo-pyran-2-one), a 2nd generation anti coagulant rodenticide, has two chiral centers, and thus four enantiomers. It is common practice to isolate the enantiomer pairs from each chiral center and then optimize their individual separation using a second chromatography method. We evaluated the effect of varying mobile phase composition on the separation of the four enantiomers in a single chromatography method on Chiracel OD-H, Chiralpak AD-H, Chiracel OJ-H and Chiralpak AS-H, 250 x 4.6 mm columns. The mobile phase combinations and solvent volume percent ranges we evaluated were: 1. hexane (60-95%)/isopropyl alcohol (5-40%). 2. hexane (80-95%)/ethanol (5-20%). 3.hexane (60-95%)/methanol:ethanol (1:1) (5-40%). The hexane/isopropyl alcohol mobile phase provided baseline resolution between the enantiomer pairs associated with each chiral center on the Chiralpak AD-H column under the conditions investigated. This approach will be used for the isolation of brodifacoum enantiomers to permit improved risk characterization for wildlife which feed on brodifacoum poisoned target species. |
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New Developments and Issues in Agrochemical Sciences
8:00 AM-11:00 AM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Agrochemicals |