Inter-Lab Variation in the Cannabis Industry, Part II: Solutions

June 11, 2019

Abstract / Synopsis:
In the first installment of this two-part series, I discussed the problem of inter-laboratory variation in the cannabis testing industry. In this second installment, I offer potential solutions to the problem. These include more and better state oversight, proper sample storage, industry agreement on standard methods, and orthogonal testing. Despite its prevalence, I believe the inter-laboratory variation problem is solvable.



It is hard to believe that we are already up to the fifth installment of this column. To review, the previous columns introduced the scope and purpose of the series (1), discussed error, precision, and accuracy (2), covered the problem of inhomogeneous samples (3), and in the last column I shared with the industry my thoughts on the problem of inter-laboratory variation and its causes (4). Here is that list of the causes as I see them:

  1. Lack of standard methods
  2. Sample inhomogeneity
  3. Lack of appropriate standards
  4. Sample preparation variability
  5. Sample instability
  6. Large factor dilutions
  7. Treating analytical methods as intellectual property
  8. Human error

It’s a long list and the cause of a complex and knotty problem. I have been a practicing analytical chemist for four decades, and been intimately involved in cannabis analysis since 2014, when it was first legal to do so. Therefore, I believe I am uniquely qualified to take a step back, analyze the problems of the cannabis analysis industry, and suggest solutions. I do this not out of malice but love. The newly opened field of cannabis science is like an unexplored continent, where every day fascinating new discoveries are being made that might benefit mankind. For those discoveries to bear fruit, the industry must be based on science and professionalism. These solutions then are offered in the hope of making a small contribution to this goal. Each solution detailed below will address one or more of the causes of the inter-laboratory variation problem discussed in the last column.

Potential Solutions

The ultimate solution to many of the causes of the cannabis laboratory inter-laboratory variation problem is legalization of marijuana at the federal level in the United States. This would allow cannabis scientists to come out from the shadows, pursue all research avenues, and feel free to share their work. It would allow the U.S. Food and Drug Administration (FDA) to become involved in the regulation of the manufacturing and analysis of cannabis medicines, and it would give a green light to the National Institute of Standards and Technology (NIST) to issue appropriate cannabis standard reference materials (SRM).

However, until that happy day comes, we as an industry will have to struggle with and try to solve this problem on our own. I believe that if we can make progress it will raise public confidence in our ability to make safe and effective medicines, increasing the likelihood of expanded legalization. Meanwhile, here are steps we can take now to start solving the problem.

  1. B.C. Smith, Cannabis Science and Technology 1(3),10-12 (2018).
  2. B.C. Smith, Cannabis Science and Technology 1(4),12-16 (2018).
  3. B.C. Smith, Cannabis Science and Technology 2(1),14-19 (2019).
  4. B.C. Smith, Cannabis Science and Technology 2(2), 12-17 (2019).
  5. B.C. Smith, P. Lessard, and R. Pearson, Cannabis Science and Technology 2(1), 48-53 (2019).
  6. B. Young, The Seattle Times January 5, 2016.
  8. M. Starks, Marijuana Chemistry (Ronin Publishing, Oakland CA, 1977).
  9. J. Fairbairn, J. Liebmann, and M. Rowan, Journal of Pharmacy and Pharmcacology, 28(1) (1976).
  10. I. Trofin, G. Dabija, D. Vaireanu, and L. Filipescu, Revista de Chimie (Bucharest), 63(293) (2012).
  11. C. Lindholst, Australian Journal of Forensic Sciences 42(181) (2010).
  12. B.C. Smith, Terpenes and Testing, Nov.-Dec. pg. 48 (2017).
  13. B.C. Smith, Terpenes and Testing, Jan.-Feb. pg. 32 (2018).
  14. J. Strull, private communications.


Brian C. Smith, PhD, is Founder, CEO and Chief Technical Officer of Big Sur Scientific in Capitola, California. Dr. Smith has more than 40 years of experience as an industrial analytical chemist having worked for such companies as Xeros, IBM, Waters Associates, and Princeton Instruments. For 20 years he ran Spectros Associates, an analytical chemistry training and consulting firm where he improved their chemical analyses. Dr. Smith has written three books on infrared spectroscopy, and earned a PhD in physical chemistry from Dartmouth College.


How to Cite This Article
B.C. Smith, Cannabis Science and Technology 2(3), 10-14 (2019)