Publications by authors named "Yannick Lassalle"
Article Synopsis
- UV-visible light exposure of thiophanate-methyl (TM) produced nine new photoproducts, with significant characterization done using advanced mass spectrometry techniques.
- Contrary to previous studies that highlighted carbendazime as the main metabolite of TM, this research found a notable isomer called PP2 instead.
- When grape berries and cherry tomatoes were treated with TM and irradiated, both TM and PP2 were found in their skins and flesh, and it was observed that irradiation time increased the ecotoxicity, particularly due to the effects of PP2.
Rationale: Fenbuconazole is a fungicide commonly used for the protection of vineyards, vegetables and grain crops. Under UV-visible irradiation, it undergoes isomerization through various cyclization processes. Isomeric structures were elucidated by liquid chromatography/high-resolution multiple-stage mass spectrometry (LC/HR-MS(n) ) coupling.
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- Researchers studied the effects of UV-visible light on the fungicide fludioxonil, using two types of photoreactors, and found that only one main photoproduct was formed.
- This photoproduct, identified as 2-(2,2-difluorobenzo[d][1,3]dioxol-4-yl)-2-(nitrosomethylene)-4-oxobutanenitrile, significantly increased the toxicity of fludioxonil in tests with Vibrio fischeri bacteria.
- Testing on grape berries showed that both fludioxonil and its photoproduct remained in the fruit even after rinsing with water, raising concerns about the effectiveness of washing produce to remove these substances
The UV-vis photodegradation of iprodione in water was investigated with a high pressure mercury lamp photoreactor. Five photoproducts of iprodione were characterized by LC-HR-MS/MS and isotopic labeling; none of them has been reported in previous studies. Three of them result from the elimination of one or two chlorine atoms followed by hydroxy or hydrogen addition while the two others are cyclic isomers of iprodione.
View Article and Find Full Text PDFRationale: Boscalid is a carboximide fungicide mainly used for vineyard protection as well as for tomato, apple, blueberry and various ornamental cultivations. The structural elucidation of by-products arising from the UV-visible photodegradation of boscalid has been investigated by gas chromatography/multi-stage mass spectrometry (GC/MS(n) ) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) couplings. The potential toxicities of transformation products were estimated by in silico calculations.
View Article and Find Full Text PDFHydrophilic interaction LC was investigated in hydro-organic and nonaqueous elution modes on a titania column by using a set of N-methyl xanthines as neutral polar probes. To get information regarding the mechanisms that are behind the discrimination of these analytes in hydrophilic interaction, we focused our study on the type and amount of organic modifier as a critical yet rarely explored mobile phase parameter. Several alcohols such as methanol, ethanol, and isopropanol were studied as substitutes to acetonitrile in hydro-organic elution mode.
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