Rapid, Direct Determination of Imidazolinone Herbicides in Water at the 1 ppb Level by Liquid Chromatography/Electrospray Ionization Mass Spectrometry and Tandem Mass Spectrometry

Abstract

The imidazolinones are a significant new class of low-use-rate, reduced-environmental-risk herbicides for protection of a wide variety of agricultural crops. Current analytical methodologies for the determinations of individual imidazolinones in water at the 1 ppb level involve processing several hundred milliliters of water through a series of solid-phase extraction cartridges and solvent-partitioning steps. By combining liquid chromatography with electrospray ionization mass spectrometry or electrospray ionization tandem mass spectrometry, all imidazolinones can be monitored simultaneously at the 1 ppb level with only a simple filtration prior to analysis. Recoveries from tap, lake, and well waters were essentially quantitative for each imidazolinone in both modes of analysis. Keywords: Imidazolinone; herbicides; determination; LC/ESMS; LC/ESMS/MS