What‘s hidden within the glyphosate issue?
By Dr. Stefan Kittlaus and Jochen Riehle, Eurofins Dr. Specht Laboratorien, Germany
Glyphosate is the most frequently used herbicide worldwide. Not only agricultural growers use this effective and cheap herbicide but also railroad companies to control weeds on the tracks, and local authorities to keep their sidewalks weed free.
A variety of methods have been developed to analyse residues of glyphosate in various commodities. However, besides glyphosate, formulations may also contain other ingredients with toxicological potential. Two examples are trimesium, a counterion of glyphosate, and Polyoxyethylene Tallow Amines (POEA), a group of surfactants which facilitates the absorption of the glyphosate into the plant.
Due to their high concentrations in the formulations, residues of these ingredients can also be expected to be present in commodities treated with glyphosate. This is important because the legal definition of residues for glyphosate includes the trimesium-ion. Including this ion in the residue calculation may result in a different assessment of whether a product is in compliance with regulatory limits. Similarly, the use of POEA as an additive is no longer permitted. Non Governmental Organisations (NGO's) who are already concerned about the toxicological effect of glyphosate, are showing increased interest in assessing the residue situation of these supporting analytes for which little data is available in food matrices.
Analytically, the complex composition and the lack of certified reference compounds complicate the quantification of the POEA. Dr. Stefan Kittlaus, responsible for method development at Eurofins Dr. Specht Laboratorien, presented the method development and validation strategies for the determination of POEA and trimesium in different food matrices at the European Pesticide Residue Workshop from 30th June to 3rd July 2014 in Dublin. His presentation has included first results of the screening and discussed the correlation between the occurrence of residues of glyphosate, POEA and trimesium.
For Eurofins customers, this is another example of horizon scanning to solve problems before they occur by having a proactive approach to developing methods to gain knowledge.
Contact: JochenRiehle@eurofins.de
