AOAC CASP Meeting - MYM 2020

Nature of Comment

Comment

Change/Recommendation

 67  ‐ delete ",and infant formula“  82 through 89, add CAS numbers I propose to add a paragraph prior to line 56, highlighting the Need for sample homogenization. this process step could be defined in more Detail (e.g., equipment to be used or particle size to be achieved).

Editorial

I suggest removing infant formula from the list of reference materials since it is a finished product and finished products are mentioned. In addition, I suggest adding the CAS numbers to the list of elements in Table 1 since the numbers are provided for the main elements on page 1. In my opinion, information about sample preparation is missing. A crucial step in heavy metal analysis of cannabis (no matter whether hemp or marijuana) is a thorough sample homogenization. This is, as Cannabis is know to accumulate heavy metals and this is also the reason for it's use in remediation of soil. This accumulation takes place in all plant parts (e.g., buds, stems ansd seeds), but to a different extent. As a consequence, the analysis of an inhomogeneous sample will lead to unprecise/unreproducible/unrepeatable results

Technical

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Nature of Comment

Comment

Change/Recom mendation

Applicability • You have to include more elements, because cannabis and hemp are hyper ‐ accumulators. • The following elements have been reported in the public domain: Pb, As, Cd, Hg, Ni, Si, V, B, Co, Cu, Se, Ba, Ag, Sb, Cr, Mo, Mn, Zn, Fe from a variety of sources including the growing medium, soil, fertilizers, nutrients, water, growth enhancers, environmental pollutants, and the cannabinoid extraction process. • Cr, Ni, Fe from the metallic/Stainless steel grinding/processing equipment • Pb, Cu, Zn, Ni, Cr, Fe from metallic components inside vaping devices heating coils, solder joints, tanks etc Analytical Technique • ICP ‐ OES will not quantitate at 10 ppb with good statistical reproducibility. D/Ls of Pb /Cd, as, Hg are only 1 ppb. Definitions • LOQ: What does "that can be reported at a quantitative result" mean...you have to give this statistical boundaries to have any real meaning. Check out EPA or USP definitions for guidance. • Repeatability:This very confusing. Do you man short term RSD of 2 or 3 replicate measurements. If you do you have to define a measurement or integration time. Check out instrument vendors definition of short term precision for guidance. • Reproducibility: What is meant by "RSD calculated from among laboratory data." Do you mean reproducibility over extended periods/intervals of time, or with different instruments and/or different operators. You have to be more clear. Check out USP Chapter 233 for guidance.

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