RAPID-DETERMINATION OF IMAZAPYR IN CORN BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY WITH ELECTRON-CAPTURE NEGATIVE-ION CHEMICAL-IONIZATION

Imazapyr, an imidazolinone class herbicide, was developed recently for weed control in imidazolinone-tolerant corn, Current methods for dete rmining imidazolinone herbicides in crops involve laborious, time-cons uming cleanup procedures after extraction, We developed an extremely s imple cleanup procedure for imazapyr in corn commodities after extract ion with acidic acetone-water by using gas chromatography/mass spectro metry with electron capture negative ion chemical ionization for final detection, Method sensitivity was 50 ppb, with controls showing <5 pp b. Average recoveries from corn forage, fodder, and grain were 98, 106 , and 101%, respectively.