RAPID AND SIMPLE METHOD FOR EXTRACTION AND DETERMINATION OF IMIDAZOLINONE HERBICIDES IN SOIL

A rapid, simple and accurate method for the simultaneous determination of residues of the imidazolinone herbicides (imazapyr, imazaquin, ima zamethabenz and imazamethabenz-methyl) in soil is described. The basis of the method is the formation of a supernatant by sonication of the soil with 0.1 M KCI. After removal from the soil particles, the pestic ides are quantified by reversed-phase liquid chromatography-mass spect rometry with an electrospray interface (LC-ESI-MS). Recoveries from a variety of soil types, fortified over the range of 50 - 200 ppb, are e ssentially quantitative for each imidazolinone and the detection limit s (signal-to-noise ratio = 3) of the method are always lower than 14 n g/g.