|Lerch, Robert - Bob|
Submitted to: Symposium on the Fate and Chemistry of Modern Pesticides Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2001
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Balance (isoxaflutole, IXF) was commercially introduced in the U.S. during the 1999 growing season. Balance degrades in soil to a diketonitrile metabolite (DKN) which further degrades to produce a benzoic acid derivative (BA). Analytical techniques were developed for the analysis of IXF, DKN, and BA in water, soil, and plant tissues using high-performance liquid chromatography (HPLC) with UV detection (HPLC-UV), mass spectrometr (HPLC-MS), and tandem mass spectrometry (HPLC-MS/MS). For water analyses, samples were cleaned up by C18 or polystyrene polymer solid phase extraction (SPE). The average HPLC-UV recoveries of the 3 compounds ranged from 60-123%. HPLC-MS recoveries from water samples spiked at 0.05-2 ppb ranged from 80-129%. The limits of quantitation (LOQ) for the HPLC-UV method were 0.1, 0.1, and 0.25 ppb for IXF, DKN, and BA, respectively, whereas the LOQ of all analytes using HPLC-MS was 0.05 ppb. For both soil and plant analyses using HPLC-MS/MS methods, sample clean-up was achieved by liquid/liquid extraction followed by concentration with polystyrene polymer SPE. The average recoveries ranged from 82-112%. The LOQ were 0.06 ppb for soil and 0.3 ppb for plant samples. These developed methods can be applied to determine the fate of Balance in the environment.