1668-54-8Relevant articles and documents
Study of the hydrolysis of a sulfonylurea herbicide using liquid chromatography with diode array detection and mass spectrometry by three-way multivariate curve resolution - Alternating least squares
Bezemer,Rutan
, p. 4403 - 4409 (2001)
This research is focused on the development of a novel, automated chemometric method for obtaining relevant chemical information from time-course measurements of an evolving chemical system. This paper describes an investigation of the hydrolysis of Ally, which is a sulfonylurea herbicide. The hydrolysis of this compound is observed at different pHs and temperatures by reversed-phase liquid chromatography using a diode array detector. The data are analyzed using a three-way, multivariate curve resolution technique. Of special interest was the application of a closure constraint in the kinetic dimension followed by the determination of the rate constants for each step of the pathway by using a differential equation solver and nonlinear fitting of the data.
Collection of ion-trap mass spectre of sulfonylurea pyrolysis products
Galletti,Dinelli,Chiavari
, p. 333 - 338 (1995)
The pyrograms of 14 sulfonylureas, i.e. herbicides characterized by high biological activity and low application dose are discussed and the mass spectra of over 30 relevant pyrolysis products as obtained with a heated filament pyrolyzer interfaced to a capillary gas chromatograph/ion-trap detector mass spectrometer are presented. Such a data compilation is useful for diagnostic purposes for both intact sulfonylureas and their metabolites after degradation in soil, because metabolites and pyrolysis products are often identical and most of their mass spectra are lacking in commercially available mass spectral libraries. The performance of the ion-trap detector based on the quality of the mass spectra is briefly discussed.
Rearrangement products in aqueous photolysis of thifensulfuron methyl
Sharma, Ashok K.,Ryan, David L.,Marr, Nina L.,Wadsley, Michael P.,Cheatham, Steve F.
, p. 401 - 410 (2017/06/29)
Photo-degradation of [14C]-thifensulfuron methyl has been investigated in aqueous media using a light source which simulates sunlight. Degradation of thifensulfuron methyl proceeds predominantly via sulfonylurea bridge ipso-contraction, and via cleavage of the bridge structure, to yield products in which the thiophene and the triazine rings have disconnected. One significant degradation product, which accounts for nearly 10%, retained both rings with truncated bridge moiety. Surprisingly, this product had thiophene ring substituents rearranged from their original locations. Other laboratories have reported photodegradation of thifensulfuron-methyl, and identified similar degradation products as well. The structure of the rearrangement product has been misidentified in previous reports because the rearrangement of the thiophene ring is not widely recognized. An unambiguous identification of this product and potential rearrangement mechanisms are presented in this report.
Simulated sunlight-induced photodegradations of triasulfuron and cinosulfuron in aqueous solutions
Vulliet,Emmelin,Grenier-Loustallot,Paisse,Chovelon
, p. 1081 - 1088 (2007/10/03)
To elucidate the photochemical behavior of two sulfonylureas (cinosulfuron and triasulfuron) for which the chemical formulas are relatively close, their photodegradation was studied in water. All experiments were carried out under laboratory conditions using a xenon arc lamp as the source of radiation to simulate environmental conditions. Polychromatic quantum efficiencies were calculated to determine the photochemical pesticide lifetimes at pH 7, and a comparison with hydrolysis lifetimes has been performed. The results obtained showed clearly that at pH 7, photodegradation becomes a more important pathway than chemical degradation. HPLC-DAD was used to study the kinetics for both sulfonylureas and their photoproducts, whereas HPLC-MS (ESI in positive and negative modes) was used to identify photoproducts. These results suggest that the photodegradation of these two sulfonylureas proceeds via a number of reaction pathways: (1) cleavage of the sulfonylurea bridge; (2) desulfonylation, which can proceed either by a carbon-sulfur cleavage or a nitrogen-sulfur cleavage; (3) O-demethylation of methoxy moieties present on the triazine ring; and (4) O-dealkylation of benzene derivatives. In addition, it was found that the desulfonylation represented the main step and that it was wavelength dependent.
