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Description of the High-Pressure Liquid Chromatography-Triple Quadrupole Mass Spectroscopy (LC-MS/MS) Test Method Used to Measure Glyphosate and AMPA in Ben & Jerry’s Ice Cream

On July 25, 2017, the New York Times reported on the results of tests the Organic Consumers Association asked an independent lab to conduct on 11 samples of Ben & Jerry’s ice cream. Ten of the 11 samples tested positive for glyphosate, the key ingredient in Monsanto’s Roundup herbicide, and/or AMPA, glyphosate’s main metabolite. The flavors we tested were: Peanut Butter Cup, Peanut Butter Cookie, Vanilla (2 samples), Cherry Garcia, Phish Food, The Tonight Dough, Half Baked, Chocolate Fudge Brownie, Americone Dream and Chocolate Chip Cookie Dough. Cherry Garcia was the only flavor that tested negative for glyphosate and/or AMPA.

The following describes the testing methodology utilized by Health Research Institute Laboratories, an independent, 501(c)(3) non-profit analytical chemistry laboratory, which conducted the tests.

Sample Homogenization
From each ice cream flavor, a representative sample, including cookie dough, waffle cones, chocolate chips, nuts, fruit, etc., was ground up with a high speed grinder, resulting in a uniform fluid that was representative of the total content of that particular ice cream flavor. 

Sample Extraction 
Each sample was then subjected to an extraction procedure involving physical and chemical fractionation steps to remove interfering substances and concentrate the glyphosate and AMPA. 

Sample Testing
Each extract was then subjected to high-pressure liquid chromatography (LC), that further fractionated the sample. Each fraction from the LC was fed into a triple quadrupole mass spectrometer (MS/MS), an instrument capable of very specifically detecting and identifying different molecules and measuring very precisely the amount of each molecule in the sample. This equipment is typically called “high-pressure liquid chromatography-triple quadrupole mass spectroscopy” or “LC-MS/MS” for short. LC-MS/MS is considered the gold standard for analysis of food samples for chemical residues like glyphosate and AMPA.

Calculation of Test Results
The concentrations of glyphosate and AMPA in a given sample are calculated by comparing the LC-MS/MS signal obtained from that ice cream sample to the signals from a series of standards of known concentration. 

The test includes process controls that account for the efficiency of recovery of the glyphosate and AMPA during the homogenization and extraction process, and also account for effects that other molecules in the sample may have on the MS/MS detection system (these are called matrix effects). 

The test is integrated with a validation process that employs statistical analysis to define accuracy, precision, limits of quantitation and detection, as well as other analytical characteristics of the method. 

The limit of detection (LOD) for the ice cream test is 0.05 parts per billion. The limit of quantitation (LOQ) is 0.25 parts per billion.

Testing was performed by Health Research Institute Laboratories, an independent, 501(c)(3) non-profit analytical chemistry laboratory.