AOAC SPSFAM PAC ERP

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?

Not provided.

No. This method should be written up as an SOP with clear steps between sample preparation and thiolysis as these steps are not clear. There is little information pertaining to the amount of SPE extract that should undergo the further reactions. Additional information regarding the calculations of total procyanidins should also be clarified to make it simply for adoption of the method. The current calculations are not clear.

New thiolysis reaction not requiring toluene-a-thiol (less odor issues). Complete thiolysis of procyanidin B2, with retention of procyanidin A2.

Poor recovery and less than desirable precision (although more studies should be conducted to confirm this). Likely due to number of steps in sample preparation and potential losses during SPE clean-up and thiolysis.

7. Any general comments about the method?

The steps within the sample preparation are not clear/concise. The precision and recovery of the method are outside that specified in the SMPR and the calculations were difficult to follow.

Recommendation for the Method

V. Final Recommendation 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.

No. There are several drawbacks to this method that would require further investigation to prove the efficacy and performance of the method. The current recovery and repeatability data are outside those specified in the SMPR.