NEGATIVE-ION MASS-SPECTROMETRY OF SULFONYLUREA HERBICIDES

Sulfonylurea herbicides have been studied using negative-ion desorption chemical ionization (DCI) mass spectrometry (MS) and DCI-MS/MS techniques. Both [M - H](-) and M(-.) ions were observed in the DCI mass spectra. The collisionally activated dissociation (CAD) spectra were characteristic of the structure of the herbicides examined. The fragmentation pattern was established based on the tandem mass spectra of the in situ deuterated sulfonylureas and on the comparison of the CAD spectra of sulfonylurea fragment ions with the CAD spectra of the ions derived from saccharin (o-benzoic sulfimide) and methyl 2-(aminosulfonyl)beozoate.