New Photodegradation Products of the Fungicide Fluopyram: Structural Elucidation and Mechanism Identification

Abstract

Identifying the fate of agrochemicals is important to understand their potential risk for living organisms. We report here new photodegradation products (PPs) of the fungicide fluopyram. The PPs were produced by irradiating a fluopyram standard in 0.1% acetonitrile aqueous media by a 150-W medium pressure Hg-lamp that emits wavelengths between 200–280 nm. The structural elucidation of PPs was achieved by combining the retention time, isotopic pattern, targeted fragmentation, and accurate mass measurements using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high resolution-MS (HRMS). In addition to previously known PPs, seven new PPs of fluopyram were identified in this work: mainly dihydroxyl and hydroxylimide fluopyram as well as mono, di, and trihydroxyl lactam. Additionally, two PPs were found to be formed by rearrangement after the loss of H2C=CH2. Hence, the results of the work contribute to extending the current knowledge regarding the photoinduced fate of agrochemicals, and fluopyram in particular.

Design, Synthesis, and Biological Activities of Novel 1,3,5-Trimethylpyrazole-Containing Malonamide Derivatives

“…In most SDHI fungicides, two aromatic moieties are connected directly via a carboxamide. However, isofetamid C (Figure 1) and fluopyram D (Figure 1), in which two aromatic moieties are bridged by an N -ethyl carboxamide or N -oxo-ethyl carboxamide, also exhibit excellent fungicidal activity, demonstrating the possibility of discovering new compounds by modifying the connection between the two aromatic moieties [21,22].…”

Optimization and validation of liquid–liquid extraction with low-temperature purification (LLE-LTP) for determining fluopyram fungicide in water samples using HPLC-DAD

“…Previous studies have employed the same combination of organic solvents as the mobile phase for determining fluopyram by HPLC in water and food samples. 11,18,19…”

“…However, MRL values for uopyram in water were not found, probably because it is a relatively new pesticide. 18,28 However, LOQ values in the range of 5 to 10 mg kg À1 have been reported in previous studies which analyzed uopyram in fruits and vegetables samples using the QuEChERS method, 28,29 liquid-liquid extraction 3 and solid phase extraction. 30 Thus, the LOQ values reached in this study are within the values found in the literature.…”

“…Previous studies have employed the same combination of organic solvents as the mobile phase for determining uopyram by HPLC in water and food samples. 11,18,19 The third parameter evaluated was the mobile phase ow (Table 1), and the obtained chromatograms are presented in Fig. S5.…”

Photoproducts of the Photodynamic Therapy Agent Verteporfin Identified via Laser Interfaced Mass Spectrometry

“…ESI mass spectral analysis of photolysed solutions has been shown to be a useful tool for identifying photoproducts. For example, solution-phase photodegradation with ESI-MS identification of photoproducts was used in studies of quercetin, a food pigment, and fluopyran, a fungicide [ 34 , 35 ]. Similarly, ESI-MS analysis of the photolysed solutions of verteporfin in this study led to the identification of a number of photoproducts, tentatively assigned as products associated with the loss of macrocycle conjugation likely due to reaction with oxygen.…”