The study, which includes contributions from Angelika Steinborn, Lutz Alder, Britta Michalski, Paul Zomer, Paul Bendig, Sandra Aleson Martinez, Hans G. J. Mol, Thomas J. Class, and Nathalie Costa Pinheiro, describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk.
Glyphosate is under threat from legislation after some studies linked the weedkiller to cancer.
The analytical methods are based on liquid chromatography–tandem mass spectrometry (LC-MS/MS) and gas chromatography–tandem mass spectrometry (GC-MS/MS), respectively.
For LC-MS/MS, sample preparation involved an ultrafiltration followed by chromatography on an anion exchange column.
The analysis by GC-MS/MS involved an extraction step, cleanup on a cation exchange column, and derivatization with heptafluorobutanol and trifluoroacetic acid anhydride.
Both methods were newly developed for breast milk and are able to quantify glyphosate residues at concentrations as low as 1 ng/mL.
The methods were applied to quantify glyphosate levels in 114 breast milk samples, which had been collected from August to September of 2015 in Germany.
The mothers participated at their own request and thus do not form a representative sample. In none of the investigated samples were glyphosate residues above the limit of detection found.
Researchers were from Federal Institute for Risk Assessment, Department of Pesticides Safety; RIKILT Wageningen UR, Natural Toxins and Pesticides; PTRL Europe; and Governmental Institute of Public Health of Lower Saxony.
The Information Technology and Innovation Foundation (ITIF), a US science and tech policy think tank, released a statement from senior fellow Val Giddings: "Using the most sensitive analytical techniques available, these researchers were unable to find any evidence of glyphosate in mother’s milk from 114 German mothers who volunteered for the study. This is yet another demonstration that the attack being waged on the world’s most widely used weed killer is unwarranted and ill considered. Farmers need all the tools they can get to keep us fed and clothed, and taking these tools away despite repeated demonstrations of their value and safety is in no one’s interest."