ORGANIC 1 ORGANIC 2 ORGANIC 3 CONVEN. 1 CONVEN. 2 CONVEN. 3 CONVEN. 4 CONVEN. 5 CONVEN. 6

0

200

400

600

800

1000

1200 ng/g

Justine M. Cruz, Jacolin A. Murray and Katrice A. Lippa

National Institute of Standards and Technology, Chemical Sciences Division, Gaithersburg, MD 20899, USA

justine.cruz@nist.gov jacolin.murray@nist.gov katrice.lippa@nist.gov

NIST FOOD SAFETY WORKSHOP | October 28-30, 2019 | Gaithersburg, MD

HOW ARE GLYPHOSATE AND AMPA ANALYZED AND MEASURED?

WHAT LEVELS WERE FOUND IN THE COMMERCIALLY AVAILABLE BREAKFAST CEREALS?

WHAT SHOULD BE DONE NEXT TO DEVELOP THE REFERENCE MATERIAL?

OBJECTIVES OF THE STUDY:

- Optimize and validate a robust method for the extraction and analysis of glyphosate (and AMPA)

- Apply the method for the screening of commercially available oat-based breakfast cereals to look for candidate reference materials

GLYPHOSATE

Multipurpose weed killer

Also used as “harvest-aid”

Quantified up to 3 ppm in 

oat based breakfast cereals 

(EWG, 2018)

Accurate measurement 

in oats needed

Dominant pesticide worldwide 

125,384 tons applied in the 

U.S. in 2014

(Benbrook, 2016)

Very polar pesticide

= difficult to extract and 

analyze

THERE IS A NEED FOR MATRIX RELEVANT 

REFERENCE MATERIALS

AMPA

DISCLAIMER

Certain commercial equipment, instruments, software, or materials are identified in this presentation in order to specify

the experimental procedure adequately. Such identification is not intended to imply recommendation or endorsement

by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment

identified are necessarily the best available for the purpose

LC-MS/MS analysis:

- Optimized for FMOC (9-fluorenylmethyl-chloroformate)

derivatized compounds

- Agilent 1290 Infinity/Agilent 6490A

- Column: ACQUITY UPLC

BEH C18 1.7 μm (Waters)

- Phases: H20 5 mmol ammonium acetate pH=9

/ Acetonitrile

METHOD PERFORMANCES:

- Validation (linearity/recoveries) for glyphosate at 5 - 1000 ng/g, for AMPA at 10 - 100 ng/g

- Limit Of Quantification = 5 ng/g for both glyphosate and AMPA

9 commercial breakfast cereals 

were tested:

oatmeal/oat-based cereals

slightly to highly processed

conventional/organic agriculture

Samples were ground into a fine 

powder before extraction

Glyphosate:

- Detected in all 9 samples

- Smaller mass fractions (under 26 ng/g) were measured in

samples from organic agriculture

- Mass fractions in samples from conventional agriculture

ranged from 62 to 1100 ng/g

AMPA:

- Not detected in 2 samples (from organic agriculture)

- Lower mass fractions than glyphosate

- Mass fractions were under 44 ng/g

WHAT DOES THE LEGISLATION SAY?

Mass fractions were < U.S EPA tolerance

= 30 ppm (30,000 ng/g) (for glyphosate in oats)

- Investigate glyphosate and AMPA stability in oat materials: How should the material be prepared? How should it be stored?

- Define the optimal mass fraction: What do the stakeholders need?

- Interlaboratory study coming soon!

Quantification:

Isotopically labelled internal

standards were added to samples

at the beginning of the extraction

Glyphosate-1,2-

13C,15N 

AMPA13C,

15N

SOLID PHASE EXTRACTION

SCREENING GLYPHOSATE AND AMPA IN OAT CEREALS FOR THE SELECTION OF CANDIDATE REFERENCE MATERIALS

WHY IS IT IMPORTANT TO DEVELOP GLYPHOSATE REFERENCE MATERIALS?

Impact on environment 

and human health?

Glyphosate degrades into 

aminomethylphosphonic acid 

(AMPA) 

No CRM available 

(in oats and other food 

matrices)

REFERENCES

Benbrook, C. M. (2016). Trends in glyphosate herbicide use in the United States and globally. Environmental Sciences Europe, 28(1), 3.

https://doi.org/10.1186/s12302-016-0070-0

EWG. (2018, October 24). Roundup for Breakfast, Part 2: In New Tests, Weed Killer Found in All Kids’ Cereals Sampled. Retrieved from

https://www.ewg.org/release/roundup-breakfast-part-2-new-tests-weed-killer-found-all-kids-cereals-sampled

ORGANIC 1 ORGANIC 2 ORGANIC 3 CONVEN. 1 CONVEN. 2 CONVEN. 3 CONVEN. 4 CONVEN. 5 CONVEN. 6

0

10

20

30

40

50 ng/g

Mass fractions (ng/g) measured in the oatmeal and oat-based breakfast cereals (n=3 replicates) Detected Not quantified Detected Not quantified Detected Not quantified Not detected Not detected 

GLYPHOSATE AMPA

1 2 3 4 5 6 7 8 9

Oatmeal Oat-based Oatmeal

ORGANIC CONVENTIONAL

1 2 3 4 5 6 7 8 9

ORGANIC CONVENTIONAL

Oat-based Oatmeal Oat-based Oatmeal Oat-based