Photolysis Pathway of Imazapic in Aqueous Solution: Ultrahigh Resolution Mass Spectrometry Analysis of Intermediates
| Autor: | M. El Azzouzi, Marianna Lucio, Mourad Harir, P. Schmitt-Kopplin, Moritz Frommberger, Andras Gaspar, D. Martens, Antonius Kettrup |
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| Rok vydání: | 2007 |
| Předmět: |
Electrospray ionization
Analytical chemistry Mass spectrometry High-performance liquid chromatography Mass Spectrometry Fourier transform ion cyclotron resonance chemistry.chemical_compound Reaction rate constant Photodegradation Chromatography High Pressure Liquid Photolysis Aqueous solution Dose-Response Relationship Drug Fourier Analysis Herbicides Imidazoles Nicotinic Acids Temperature General Chemistry Hydrogen-Ion Concentration Imazapic Kinetics Solubility chemistry Spectrophotometry Ultraviolet General Agricultural and Biological Sciences |
| Zdroj: | Journal of Agricultural and Food Chemistry. 55:9936-9943 |
| ISSN: | 1520-5118 0021-8561 |
| Popis: | Direct degradation of imazapic, an herbicide of the imidazoline family, has been investigated in aqueous solution at different concentrations, pH values, and temperatures. The efficiency of the photodegradation process has been evaluated through degradation rate constants that could be fitted best with pseudo-first-order kinetics ( Ct = C0 e(- kt )). Ultrahigh resolution mass spectrometry (FTICR/MS) was used in electrospray ionization mode as a tool to study the photolysis process on a molecular level, whereas UV-vis and high-performance liquid chromatography/mass spectrometry analysis were used to follow, by time, the evolution of the intermediates. Taking advantage of the high resolving power of FTICR/MS to perform precise formula assignments taking account of the natural abundance of isotopes, we herein propose and demonstrate an approach using 2D-derived van Krevelen visualization (O/C, H/C, m/z) to confirm the formation of imazapic intermediates. Such an approach allows a qualitative analysis of intermediates and elucidates the plausible reaction pathways of the photolysis process. More than eight photoproducts were separated and identified as a phototransformation of the imidazole ring. A mechanistical pathway was proposed. |
| Databáze: | OpenAIRE |
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