AOAC SPDS ERP DECEMBER 15, 2017

2. Does the method contain system suitability tests or controls as specified by the SMPR? If not, please indicate if there is a need for such tests or controls and which ones. 3. Is there information demonstrating that the method system suitability tests and controls as specified in the SMPR worked appropriately and as expected? If no, please specify. 4. Based on the supporting information, is the method written clearly and concisely? If no, please specify the needed revisions.

The system suitability test is provided in the form of instrument precision on standards at the midrange point of the analytical range and achieved RSDs ranging from 2.8-3.8%.

The system suitability test suggests the instrumental repeatability is fairly close to the SMPR repeatability requirements, representing a large challenge.

The method as submitted does have some clarity challenges.

No column temperature is provided in the description of the separation, though AOAC Appendix K does allow for adjustments to column temperature during column lifetime. The extracted sample dilution is left to the reader to determine. It is challenging to predict the correct dilution as the analytes have a wide range of concentrations, but multiple dilutions and injections will result in decreased sample throughput.

Additionally the use of liquid nitrogen is mentioned in the supporting info but not truly incorporated into the method.

As this is a submission for the dried plant material method, it may be beneficial to remove the sections about analysis of oil for clarity. The ability of this method to analyze oil was not reviewed per the method applicability statement supplied by the author.

Lastly, it would be ideal to integrate the supplemental data into the body of the submission to make the entire method more clear.

5. Based on the supporting information, what are the pros/strengths of the method?

The use of methanol as an extraction solvent is a major improvement over 9:1 Methanol:Chloroform for laboratories and represents a major positive of this method. The method overall shows a reasonable adherence to the SMPRs tested for especially when the “non-analytical” challenges of the analyte are considered (i.e. difficulty gathering among-lab data for reproducibility, CRM concentration limits making recovery challenging).

The method is simple and could be adopted by most analysts and labs simply without major training or capital expenditure required.