AOAC_SPDS_ERP_-_Set_3

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. 5. Based on the supporting information, what are the pros/strengths of the method? 6. Based on the supporting information, what are the cons/weaknesses of the method?

Yes. A blank check sample could be added to comply with SMPR.

Yes.

Yes. I would add more guidance under the section for sample preparation to assist in choice of sample size and extraction volume. Something like "Choose sample size corresponding to approximately X mg of catechins/analytes".

The method is simple and straightforward (sonication extraction, chromatography, detection). This method could be easily implemented in any laboratory.

The chromatography is fast and appears to separate the 8 compounds of interest.

The method has not demonstrated accuracy via use of reference materials or spike/recovery studies. The method may benefit from inclusion of an internal standard.

The method has not demonstrated adequate precision as specified in the SMPR.

The method has not demonstrated adequate linearity, LOQ, and LOD as stated in the SMPR.

Unknown how method would respond to additional matrices specified in the SMPR, particularly gummies/chewables (2 difficult matrices). Sonication extraction might not be sufficient. This is a good start, but even for the limited number of compounds and matrices included, most of the SMPR requirements are not met. A significant amount of work is needed before this method will meet the SMPR. At this time, I do not recommend this method for first action status. Additional work is needed to include more matrices (and possibly more analytes), and to improve the separation and/or extraction to address the high recovery values. Inclusion of an internal standard may help. If someone is willing to take this on, the method seems to be a good place to start.

7. Any general comments about the method?

Do you recommend this method be adopted as a First Action and published in the Official Methods of Analysis of AOAC INTERNATIONAL? Please specify rationale.