Identification of adjuvants in plant protection products applying a suspect screening workflow based on orthogonal techniques

Suspect screening of pesticide co-formulants in fruits, vegetables and leaves by liquid and gas chromatography coupled to high resolution mass accuracy spectrometry: Potential impact on human health

Vegetables can contain co-formulants derived from the use of plant protection products (PPPs) in crops. Thus, in the current study co-formulants were determined in different fruits and vegetables and their leaves by gas and liquid chromatography coupled to Q-Orbitrap high-resolution mass spectrometry (GC-Q-Orbitrap and LC-Q-Orbitrap-MS). A total of 37 co-formulants were tentatively identified, and among them, 12 compounds were quantified by LC-Q-Orbitrap-MS and 9 by GC-Q-Orbitrap-MS. The mean co-formulant levels in fruit and vegetable samples was 92% lower than in leaf samples. Selected samples showed a high concentration of 1-ethyl-2-pyrrolidone among the co-formulants detected. This compound ranged from 22 µg/kg (strawberry) to 722 µg/kg (red grape), whereas in the case of leaves, its concentration was up to 6513 µg/kg in cucumber leaf. In addition, it has an LD50 equal to 1.440 g/kg. Therefore, this type of PPP co-formulants should be controlled in fruits and vegetables to avoid adverse health effects.

Unveiling Coformulants in Plant Protection Products by LC-HRMS Using a Polyhydroxy Methacrylate Stationary Phase

A polyhydroxy methacrylate-based stationary reversed phase was used for the determination of coformulants in 20 plant protection products (PPPs). These samples were analyzed by liquid chromatography coupled to Q-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap-HRMS) in full-scan MS and data-dependent acquisition (ddMS2) modes. A total of 92 coformulants were tentatively identified in these formulations by nontargeted and unknown analyses. Twelve out of them were quantified by analytical standards. The most concentrated coformulant was the anionic surfactant dodecylbenzenesulfonic acid, whose highest content was obtained in the Score 25 sample (6.87%, w/v). Furthermore, triethylene glycol monomethyl ether, 4-s-butyl-2,6-di-tert-butylphenol, 1-ethyl-2-pyrrolidone, sorbitan monostearate, 2,6-dimethylaniline, palmitamide, and N-lauryldiethanolamine were quantified for the first time in these products. Hence, the polyhydroxy methacrylate-based stationary phase increased the identification of new coformulants in PPPs, being complementary to conventional C18. This strategy could be applied in future studies to estimate potential coformulant residues from PPPs applied to crops.

Characterization of the composition of plant protection products in different formulation types employing suspect screening and unknown approaches

BACKGROUND

Plant protection products (PPPs) are used extensively in agriculture to control crops. These PPPs, which may be found in different types of formulations, are composed of a designated pesticide (active principle) and other inactive ingredients as co-formulants. They perform specific functions in the formulation, as solvents, preservatives or antifreeze agents, among others.

RESULTS

A research technique based on ultra-high-performance liquid chromatography (UHPLC) coupled to a Quadrupole-Orbitrap mass analyzer was successfully applied to characterize the composition of six different PPPs in terms of the presence of co-formulants and types of formulations: emulsifiable concentrate (EC), emulsion in water (EW), suspension concentrate and water-dispersible granule. These PPPs (FLINT MAX, MASSOCUR 12.5 EC, IMPACT EVO, TOPAS, LATINO and IMPALA STAR) had antifungal activity, containing one triazole compound as active principle (tebuconazole, penconazole, myclobutanil, flutriafol or fenbuconazole, respectively). Non-targeted approaches, applying suspect and unknown analysis, were carried out and ten compounds were identified as potential co-formulants. Six (glyceryl monostearate, 1-monopalmitin, dimethyl sulfoxide, N,N-dimethyldecanamide, hexaethylene glycol and 1,2-benzisothiazol-3(2H)-one) were confirmed by injecting analytical standards. Finally, these compounds were quantified in the PPPs.

CONCLUSION

The current study allowed for detecting co-formulants in a wide range of concentrations, between 0.04 (dimethyl sulfoxide) and 19.00 g L^-1 (glyceryl monostearate), highlighting the feasibility of the proposed analytical methodology. Moreover, notable differences among the types of formulations of PPPs were achieved, revealing that EC and EW were the formulations that contained the largest number of co-formulants (four out of six detected compounds). © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of Co-Formulants in Marketed Plant Protection Products by LC-Q-Orbitrap-MS: Application of a Hybrid Data Treatment Strategy Combining Suspect Screening and Unknown Analysis

The aim of this study was the determination of co-formulants in 15 different chlorantraniliprole- and difenoconazole-based plant protection products (PPPs) belonging to different formulations. Samples were analyzed by ultrahigh-performance liquid chromatography coupled to Q-Orbitrap high-resolution mass accuracy spectrometry (UHPLC-Q-Orbitrap-MS), operating in full-scan MS and data-dependent acquisition (ddMS²) modes. A total of 78 co-formulants were tentatively identified by a combination of suspect screening and unknown analysis. Nine of them were later confirmed by analytical standards. Finally, the analytical method was successfully validated and co-formulants were quantified. Linear alkyl ethoxylates (LAS) were the most common type of co-formulant, followed by sodium alkylbenzene sulfonates. Moreover, sodium dodecyl benzene sulfonate had the highest concentration of any co-formulant (up to 32.33 g/L). In all, an innovative identification of co-formulants in a large number of PPPs is presented, which will give room for future studies delving into the composition of PPPs or determining these co-formulants in environmental or agricultural samples.

Co-formulants in plant protection products: An analytical approach to their determination by gas chromatography-high resolution mass accuracy spectrometry

In the present study, 12 volatile benzene and naphthalene derived co-formulants were identified by suspect screening and unknown analysis in 14 plant protection products (PPPs) corresponding to several types of formulations, as emulsifiable concentrates (EC), suspension concentrates (SC), dispersible concentrates (DC) and ZC, which is a mixture of a capsule suspension (CS) in an SC, containing either difenoconazole or chlorantraniliprole as main active ingredients. The selected technique was gas chromatography coupled to Q-Orbitrap high resolution mass accuracy spectrometry (GC-Q-Orbitrap-MS), providing efficient separation and detection of all identified compounds. Finally, 42 compounds were tentatively identified, and 12 of them were confirmed and quantified using analytical standards. Results showed that the applied methodology was able to detect these co-formulants at concentrations as low as 0.03 g/L (tert-butylbenzene), encompassing a wide concentration range, up to 9.63 g/L (pentamethylbenzene). Pentamethylbenzene was the only compound detected in all studied samples.