Looking beyond the Active Substance: Comprehensive Dissipation Study of Myclobutanil-Based Plant Protection Products in Tomatoes and Grapes Using Chromatographic Techniques Coupled to High-Resolution Mass Spectrometry

Abstract

A comprehensive evaluation of the dissipation of a myclobutanil plant protection product was performed in tomato and grape samples. Different temperature conditions (3 and 22 °C) were evaluated. A biphasic kinetic model provided a suitable adjustment (R 2 > 0.95), with persistence (residual level, RL 50 ) lower than 24 days in all cases. Solid−liquid extraction and ultra-highperformance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS) were used for metabolites' elucidation, identifying six myclobutanil metabolites, four out of them described for the first time and one of them confirmed using 1 H, 13 C, ( 1 H-1 H)-COSY, ( 1 H-13 C)-HMQC, and ( 1 H-13 C)-HMBC nuclear magnetic resonance (NMR). Their degradation curves were also evaluated, increasing their concentrations when the myclobutanil concentration decreases. Additionally, coformulants present in the commercial formulation were monitored employing headspace solid-phase microextraction method (HS-SPME)-gas chromatography coupled to HRMS (GC-Q-Orbitrap-HRMS). Seven coformulants were quantified in tomato samples. Their dissipation curves were studied, and it was observed that they were almost degraded 12 days after application.

Uncovering the Dissipation of Chlorantraniliprole in Tomatoes: Identifying Transformation Products (TPs) and Coformulants in Greenhouse and Laboratory Studies by UHPLC-Q-Orbitrap-MS and GC-Q-Orbitrap-MS

“…In a previous study, Marín-Sáez et al confirmed seven volatile coformulants in tomato samples sprayed with Mitrus, a myclobutanil PPP under laboratory conditions. Similarly, four of these coformulants (or their isomers) were also detected in the present study, which include pentamethylbenzene, 1,2,4-trimethylbenzene, 2-methylbiphenyl, and tert -butylbenzene.…”

“…studied the presence of representative anionic surfactants and solvents in different crops treated with PPPs based on several types of formulations by liquid chromatography coupled to tandem mass spectrometry (LC-QqQ-MS/MS). Furthermore, Marín-Sáez et al confirmed several volatile and nonpolar coformulants in laboratory studies in tomatoes by gas chromatography coupled to Q-Orbitrap high-resolution mass spectrometry (GC-Q-Orbitrap-MS).…”

“…However, previous dissipation studies in other matrices also show a biphasic model fit for other pesticides, which supports our findings. 7,30,31 3.2.2. Greenhouse Studies.…”

“…Nonetheless, during the dissipation of pesticides, several TPs of different toxicities could be generated from the parent pesticide, some of which could even be far more toxic than the active substance itself, as previous studies have pointed out. 7,12 Therefore, this fact could clearly pose a direct risk to consumers exposed to products treated with chlorantraniliprole. However, other studies point in the opposite direction, suggesting low toxicity for mammalians, based on the fact that it is considered to be highly selective for insect ryanodine receptor, 1,2 which, in turn, does not mean that it is not toxic for mammalians.…”

Unravelling plant protection product analysis: Use of chromatography techniques (GC and LC) and high resolution mass spectrometry

“…For instance, HS was used for the determination of volatile compounds as toluene or benzene [18,19]. HS-SPME was used for the monitoring of co-formulants in a myclobutanil PPP (Mitrus) by GC-HRMS, allowing the detection of seven benzene derivate compounds [45]. In this work, HS-SPME was compared with liquid injection, demonstrating being more adequate for the analysis of volatile compounds, due to the low detection limits obtained compared to liquid injection.…”