Glyphosate levels reported in this study are from foods purchased between January and June 2020 and represent a snapshot of glyphosate contamination in hummus, chickpeas and other bean and lentil products. Actual levels of glyphosate vary by product.
All samples were purchased by EWG researchers online or at major food retailers in the Washington, D.C., New York City and San Francisco metropolitan areas, including Aldi, Costco, Giant, Harris Teeter, Safeway, ShopRite, Target, Trader Joe’s, Walmart and Whole Foods Market grocery stores. Tests were conducted by Anresco Laboratories of San Francisco, which is accredited by the state of California. For canned samples, the liquid was removed before the sample was processed, except for the canned pinto beans. All other products types were tested directly from the package.
To extract glyphosate from the product samples, the lab performed a liquid-liquid extraction, followed by a solid phase extraction. Glyphosate was then measured using liquid chromatography tandem mass spectrometry (LC-MS/MS). The methods limit of quantification for glyphosate is 5 parts per billion. The lab’s extraction and measurement methods are modified versions of methodology published by government agenciesa,b, and in the peer-reviewed literature.c,d
aChamkasem N, Morris C, Harmon T. 2015. FDA Laboratory Information Bulletin Direct Determination of Glyphosate, Glufosinate, and AMPA in milk by Liquid chromatography/tandem mass spectrometry.
bAnastassiades et al. 2016. EU Reference Laboratories for Residues and Pesticides v. 9.1 Quick Method for the Analysis of numerous Highly Polar Pesticides in Foods of Plant Origin via LC- MS/MS involving Simultaneous Extraction with Methanol (QuPPe-Method).
cNagatomi et al. 2013. Simultaneous LC-MS/MS Analysis of Glyphosate, Glufosinate, and Their Metabolic Products in Beer, Barley Tea, and Their Ingredients. Biosci. Biotechnol. Biochem., 77 (11), 2218-2221
dHanke I, Singer H, Hollender J. 2008. Ultratrace-level determination of glyphosate, aminomethylphosphonic acid and glufosinate in natural waters by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry: performance tuning of derivatization, enrichment and detection. Anal. Bioanal. Chem., 391, 2265-2276.