Testing Cannabis Plant Material for Pesticides

Testing Cannabis Plant Material for Pesticides

Professor DeBacco


Research Article
Nie, B., Henion, J., & Ryona, I. (2019). The role of mass spectrometry in the cannabis industry. Journal of the American Society for Mass Spectrometry, 30(5), 719-730.
https://www.researchgate.net/publicat...

Pesticide Concerns
Pesticide residues have become a significant problem for the cannabis industry because the final product can be concentrated or burned resulting in alterations that do not typically occur with other plant materials.
As a result, the level of pesticides and herbicides should be very low or absent.



Not Only an Outdoor Problem
Cannabis grown in controlled indoor environments are still subject to insect, bacterial and fungal pests that can negatively impact the plants.
Due to the treat of plant loss, the use of pesticides is of increased temptation by growers.



Organic Does Not Necessarily Mean No Spray
Numerous detections of low-to-moderate levels of pesticide contamination (10’s of ppb or less) from a number of growers claiming to use “organic” or “clean green” growing methods prompted the investigation of possible sources.



Reliable Chemical Analysis is Important
Reliable chemical analysis of plant material before it is consumed is important to ensure the absence of pesticides.

Pesticide Myclobutanil Example
Myclobutanil was the most prevalent pesticide detected and is most commonly used as a treatment for mold infestations.
Myclobutanil is a fungicide that when present in cannabis plant material is smoked via a cigarette, it releases the very toxic gas, hydrogen cyanide.



State by State Lists
Each state has its own list of those pesticides which must be monitored in cannabis samples.
California, for example, currently has a list of total 66 pesticides which must be monitored where 21 in this list are in category I and should not be detected in cannabis products while the other 45 pesticides in category II should not exceed indicated action levels at low part per billion (ppb) lower limits of quantitation (LLOQ)



Cannabis Chemical Complexity
Separation and use of mass spectrometry are analytical methods that can help handle the complexities of the plant and the low ppb levels of states regulations.
Although GC/FID analyses have been employed in the past for measuring some pesticides, more recently, GC/MS, GC/MS/ MS, LC/MS, or LC/MS/MS techniques may be preferred.



Suggested Techniques
In many cases where pesticide levels are in the mid-to low ppb range, this SIM LC/MS approach may be appropriate.

For those samples containing very low ppb levels of unknown pesticides, it may be preferred to employ LC/MS/MS techniques or high-resolution MS employing a QTOF or Orbitrap


LC/MS/MS Techniques For Pesticide Detection
In general, most state laboratories, including New York state, suggest the use of LC/MS/MS techniques for the quantitative determination of pesticides in cannabis, hemp, and the products derived from them
This technology coupled with recommended sample preparation provides broad coverage with high sensitivity and selectivity for the quantitative determination of over 100 pesticides.

Challenge with Pesticide Testing
The inherent challenge is if the pesticide is not tested for it could be present but not identified.
However, having cannabis plant material testing for the likely pesticides used is an important step.

Consumers should be ensuring any product they are considering purchasing has the proper testing and this documentation is checked before buying and using.




Link to Lecture Slides: https://drive.google.com/file/d/1_ZGj...

*Due to the description character limit the full work cited for "Testing Cannabis Plant Material for Pesticides" can be viewed at... https://drive.google.com/file/d/1tb7o...