Glyphosate and AMPA determination in honey

REPETTI, MARÍA R.; DEMONTE, LUISINA D.; MAGNI, FLORENCIA V.; MICHLIG, MELINA P.; MICHLIG, NICOLÁS

Bologna

Workshop; 14TH European Pesticide Residue Workshop (EPRW); 2022

Glyphosate (N-(phosphonomethyl)-glycine) is a broad-spectrum, systemic, contact herbicide. It is a molecule that attacks all weeds except genetically modified (GM) organisms, such as soybean, corn or cotton. In this situation, Argentina is one of the pioneer countries in adopting GM crops and is one of the major producing countries after the USA and Brazil (ISAAA, 2019).A large amount of glyphosate applied worldwide, specifically in Argentina, has drastically increased the eco-toxicological environmental risk and human exposure. For this reason, concentration levels of this herbicide and its main degradation product (aminomethylphosphonic acid, AMPA) are reported in soil, water resources, rainwater and even air. This environmental contribution of glyphosate directly impacts food contamination, where Argentine honey production is strongly affected. This scenario motivated us to determine glyphosate and AMPA in honey samples from different country regions.The methodology developed in the laboratory includes an extraction stage with water due to the high solubility of these compounds, then a derivatization step with FMOC-Cl in an alkaline medium (pH = 9). Followed by a clean up by L-L partition with dichloromethane and finally analysis by liquid chromatography coupled to mass spectrometry. The guidelines proposed by SANTE for validating the analytical methodology were followed, obtaining satisfactory figures of merit. The recovery percentages were 86% and 84% for glyphosate and AMPA respectively, relative standard deviations ≤20% for both compounds. And LOQs calculates as the lower recovery level of 5 ug/kg. The derivatization step allows reaching low levels of quantification, compatible with the current demands in this type of analysis. The method was applied to the analysis of 58 commercial samples with results in the