A Robust Transferable Method for the Determination of Glyphosate Residue in Liver After Derivatization by Ultra-high Pressure Liquid Chromatography–Tandem Mass Spectrometry

The Current Status of Analytical Methods Applied to the Determination of Polar Pesticides in Food of Animal Origin: A Brief Review

The use of high polar pesticides such as glyphosate and metabolites has increased due to their low cost, low persistence in the environment and high effectiveness. The use of glyphosate is currently permitted in the European Union until 15 December 2022. However, the possible toxic effects on human health and the environment are under debate. Their widespread application on various crops might lead to residues in food intended for animal consumption. For this reason, the Commission, implementing Regulation (EU) 2021/601, recommends the analyses of polar pesticides, not only in matrices of plant origin, but also in those of animal origin such as fat, liver, milk and eggs throughout the years 2022, 2023 and 2024. The determination of polar pesticides is hampered by their chemical nature, which poses challenges both in the instrumental detection (poor column retention, low molecular weight MS/MS fragments, etc.) and in the management of matrix effects, which may vary significantly from matrix to matrix within the same food commodity group. For these reasons, nowadays, there is a limited number of methods for the detection of polar pesticides in food of animal origin. This brief review discusses the different approaches for the simultaneous determination of polar pesticides in food of animal origin using both chromatographic and non-chromatographic techniques.

Field-amplified sample injection and sweeping micellar electrokinetic chromatography in analysis of glyphosate and aminomethylphosphonic acid in wheat

Glyphosate, a widely used herbicide, has been classified as probably carcinogenic to humans by the International Agency for Research on Cancer (IARC). In the present study a method based on Field-Amplified Sample Injection and Sweeping Micellar Electrokinetic Chromatography (FASI sweep-MEKC) has been developed and validated for determination of glyphosate and its microbial metabolite aminomethylphosphonic acid (AMPA) in wheat flour. The method involved a preliminary solid phase extraction for cleanup of the aqueous extracts from wheat flour, based sequentially on C18 and strong anion exchange cartridges, followed by derivatization using 9-fluorenylmethylchloroformate. Optimization of sample cleanup and derivatization procedure was carried out by a HPLC-UV method, whereas FASI sweep-MEKC was applied for achieving the sensitivity necessary for analysis of real samples. To this regard, optimum conditions involved the use of an extended path fused-silica capillary (80 cm total length, 50 μm, i.d.) filled with a high concentration buffer (sodium phosphate 100 mM, pH 2.2). Electrokinetic sampling was carried out at -10 kV with injection time of 700 s and the separation of the loaded analytes was performed under MEKC conditions using sodium phosphate buffer 50 mM at pH 2.2, supplemented with sodium dodecyl sulfate, 100 mM. The method was validated for linearity, precision, accuracy and sensitivity, showing that using conventional UV detection (210 nm) the achieved limit of quantitation (LOQ) values for both the analytes were widely lower than those set by Authorities. In particular, LOQ for glyphosate and AMPA were found to be 5 and 2.5 ng/mL, respectively, corresponding to 0.1 and 0.05 mg/kg, in wheat flour. The method, applied to commercially available real samples (wheat flour from different manufacturers) and to an experimental sample obtained by cv. Svevo wheat, can be considered as a convenient alternative to the existing approaches in analysis of complex matrices.

A simple liquid chromatography-high resolution mass spectrometry method for the determination of glyphosate and aminomethylphosphonic acid in human urine using cold-induced phase separation and hydrophilic pipette tip solid-phase extraction

Recently, the phenomenon of acute poisoning events caused by glyphosate (GLY) had frequently occurred all over the world. The present work reported a simple liquid chromatography-high resolution mass spectrometry (LC-HRMS) method for direct determination of GLY and its metabolite aminomethylphosphonic acid (AMPA) in human urine by combining cold-induced phase separation (CIPS) with hydrophilic pipette tip solid-phase extraction (PTSPE). First, a urine sample was mixed with acetonitrile at a 80% concentration to precipitate proteins. After centrifugation, the mixture was performed a CIPS at -20 °C to enrich GLY and AMPA (six-fold) in the lower water phase which was further performed PTSPE procedure. PTSPE as a miniaturized procedure of SPE, combined with a manual accu-jet® Pro Pipette Controller, was used to extract GLY and AMPA, in which a new type of hydrophilic adsorbent (HILIC powder) based on amide-modified silica was selected as the adsorption of GLY and AMPA. The key factors including the type and the amount of adsorbent, the loading extraction solution, the type and volume of eluent, and the number of aspirating/dispensing cycles were investigated in detail. Meanwhile, the selectivity and sensitivity of GLY and AMPA analysis were improved by the use of LC-HRMS based on targeted single ion monitoring (tSIM) mode without tedious derivatization. This method made a full use of the advantages of these techniques by combining efficient enrichment, effective extraction and selective separation in a simple way. Finally, a comprehensive validation of the method was rigorously executed and the results indicated that the validated method afforded desired linearity, precision, accuracy, and sensitivity.

Effect of glyphosate on X-ray diffraction of copper films prepared by electrochemical deposition

In the process of electrochemical deposition of metals, the additives can directly affect the final morphology of the metal. Using glyphosate as the additive, copper thin films were prepared by the electrochemical deposition method from a CuSO₄ aqueous solution under a specific voltage. The copper thin films were grown on the surface of the indium tin oxide (ITO) film, which was used as the working electrode in a classical three-electrode cell. Glyphosate combined with the copper ion to form a complex, and hindered further reduction and crystallization of the copper ions. The results indicated that the peak intensities of the X-ray diffraction peaks decreased with the increase in the glyphosate concentrations, which can be used as a basis for quantitative detection. The method is simple and highly sensitive.

Quantitative probing of glyphosate by combining electrochemical deposition and X-ray diffraction methods.