Development and Application of a Novel Pluri-Residue Method to Determine Polar Pesticides in Fruits and Vegetables through Liquid Chromatography High Resolution Mass Spectrometry

Abstract

Nowadays, highly polar pesticides are not included in multiresidue methods due to their physico-chemical characteristics and therefore, specific analytical methodologies are required for their analysis. Laboratories are still looking for a pluri-residue method that encompasses the largest number of polar pesticides. The aim of this work was the simultaneous determination of ethephon, 2-hydroxyethylphosphonic acid (HEPA), fosetyl aluminum, glyphosate, aminomethylphosphonic acid (AMPA), N-acetyl-glyphosate and N-acetyl-AMPA in tomatoes, oranges, aubergines and grapes. For that purpose, an ultra high performance liquid chromatography (UHPLC) coupled to a high resolution single mass spectrometer Orbitrap-MS were used. Different stationary phases were evaluated for chromatographic separation, and among them, the stationary phase Torus DEA provided the best separation of the selected compounds. The QuPPe method was used for the extraction of the analytes, but slight modifications were needed depending on the matrix. The developed method was validated, observing matrix effect in all matrices. Intra- and inter-day precision were estimated, and relative standard deviation were lower than 19%. Recoveries were satisfactory, and mean values ranged from 70% to 110%. Limits of quantification were between 25 and 100 µg kg−1. Finally, the analytical method was applied to different fruits and vegetables (oranges, tomatoes, aubergines and grapes).

Influence of different hydrophilic interaction liquid chromatography stationary phases on method performance for the determination of highly polar anionic pesticides in complex feed matrices

“…The 14 target compounds were selected based on the priority of these compounds in European coordinated pesticide monitoring programmes and the lack of fast and efficient analytical methods that can be applied for even the most challenging matrices, such as feed samples. Similar work was recently published that also evaluated different HILIC columns, but in that case only for the relatively easier matrices of fruits and vegetable [19]. The Quick Method for the analysis of numerous highly polar pesticides in food involving extraction with acidified methanol and LC‐MS/MS measurement (QuPPe‐method) [20], developed by the European Reference Laboratory for Single residue methods, also makes use of various HILIC methods, but the columns applied are different from those in our current research and appeared to be less robust in real practice.…”

Current Role of Mass Spectrometry in the Determination of Pesticide Residues in Food

“…Single-residue methods are intended for selected pesticides that, due to their particular physicochemical properties (e.g., usually high polarity), require specific protocols for their determination [21]. The main drawbacks that prevent the simultaneous determination of these compounds with other pesticides are their low or close-to-zero affinity for the organic solvents commonly used as the extraction phase in sample treatments, and their low retention in conventional reversed-phase columns used in pesticide analysis [22]. To overcome these problems, the EU Reference Laboratories have proposed up to 11 different main single-residue methods for the determination of up to 55 polar pesticides [23].…”

“…Both issues are critical in pesticide residue monitoring because almost 800 compounds must be investigated, and the application of various methods to routinely monitor them presents serious limitations for food control laboratories [24]. Initial attempts have been made to implement multiresidue methods for highly polar pesticides, but in general these methods do not achieve the determination of 20 compounds in total [22,25,26]. In this sense, large-scale multiresidue methods refer to those capable of covering at least 80 analytes [27].…”

“…In this framework, HRMSbased methods have significantly expanded the testing scope of pesticides, monitoring almost 1000 analytes in less than 15 min [118]. Despite the fact that targeted analysis of pesticides can also be addressed by HRMS [22,154], HRMS-based workflows are primarily intended for non-targeted analysis of pesticides, including suspect screening approaches. The main objective of such methods is to determine pesticide residues in food products beyond a predefined scope of target pesticides.…”

Detection of Residual Pesticides in Foods

“…The determination of highly polar pesticides is still a problem, and laboratories are looking for a pluri-residue method that encompasses the largest number of polar pesticides. In this sense, different stationary phases have been tested, and Manzano-Sánchez et al [ 4 ] observed that the stationary phase Torus DEA provided the best separation of ethephon, 2-hydroxyethylphosphonic acid (HEPA), fosetyl aluminum, glyphosate, aminomethylphosphonic acid (AMPA), N-acetyl-glyphosate, and N-acetyl-AMPA. Previous LC separation, QuPPe method was used for the extraction of the targeted compounds, but slight modifications were necessary depending on the tested matrix (tomato, orange, aubergine, grape).…”