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 determining imidazolinone herbicides in crops involve laborious, time-consuming cleanup procedures after extraction, We developed an extremely simple cleanup procedure for imazapyr in corn commodities after extraction with acidic acetone-water by using gas chromatography/mass spectrometry with electron capture negative ion chemical ionization for final detection, Method sensitivity was 50 ppb, with controls showing <5 ppb. Average recoveries from corn forage, fodder, and grain were 98, 106, and 101%, respectively.