Direct determination of glyphosate and aminomethyl phosphonic acid in honeybees

Method of Glyphosate, AMPA, and Glufosinate Ammonium Determination in Beebread by Liquid Chromatography-Tandem Mass Spectrometry after Molecularly Imprinted Solid-Phase Extraction

The aim of this study was to develop a method for the determination of glyphosate, its metabolite aminomethylphosphonic acid (AMPA), and glufosinate ammonium residues in beebread samples, which could then be used to assess bees' exposure to their residues. The complexity of beebread's matrix, combined with the specific properties of glyphosate itself, required careful selection and optimization of each analysis step. The use of molecularly imprinted solid-phase extraction (MIP-SPE) by AFFINIMIP glyphosate as an initial clean-up step significantly eliminated matrix components and ensured an efficient derivatization step. Colorless beebread extracts were derivatized by the addition of 9-fluorenylmethyl chloroformate (FMOC-Cl). After derivatization, in order to remove FMOC-OH and residual borate buffer, a solid-phase extraction (SPE) clean-up step using Oasis HLB was carried out. Instrumental analysis was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The method was validated according to the SANTE/11312/2021 guideline at concentrations of 5, 10, and 100 µg/kg, and satisfactory recovery (trueness) values (76-111%) and precision (RSDr) ≤ 18% were obtained. The limit of quantification (LOQ) was 5 µg/kg for AMPA and glufosinate ammonium and 10 µg/kg for glyphosate. The method was positively verified by the international proficiency test. Analysis of beebread samples showed the method's usefulness in practice. The developed method could be a reliable tool for the assessment of beebread's contamination with residues of glyphosate, its metabolite AMPA, and glufosinate ammonium.

Herbicide determination in Brazilian propolis using high pressure liquid chromatography

Propolis is a widely used medicinal product sourced by bees from vegetation that may be frequently irrigated with herbicides. Exposure to herbicides can affect bees' health and the quality of commercial propolis. The objective of this study was to calculate the concentrations of glyphosate, aminomethylphosphonic acid (AMPA), picloram and atrazine in different types of propolis from Brazil using high-performance liquid chromatography (HPLC). Four types of propolis (brown, green, red, and yellow) were evaluated for a total of 19 samples. Of these types of propolis, 47% tested positive for the herbicides atrazine (5 to 17.4 µg/g) and AMPA (10.2 to 11.3 µg/g). No samples were reported to be positive for glyphosate; however, the presence of AMPA indicates its existence. The concentrations observed in this study are less than international maximum-residue-level standards.