AOAC_SPDS_ERP_-_Set_3

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?

blank injection is missing, check Standards at different concentrations are described.

yes

definitely separation power and Speed.

Methyl xanthenes (besides caffein) are missing. Gallic acid is missing though it maybe important. The method has been applied only for green tea and not for fermented black tea.

7. Any general comments about the method?

Excellent Method for green tea (and products). The method should also be tested for black tea. Usually a stabilizing solution (like in the ISO-method) should be used, to the instability of some catechins in solution. Some of the Validation Parameters doesn't fulfill the requirements of the SMPR's, e.h. recovery rate for caffeine only 78.7% for a dietary Supplement. The method could be recommended (because of speed and resolution) after having tested for black tea as well and including theobromine and theaphyllin like it is required by the SMPR. Some of the Validation data should be repeated or verified by the applicants.

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.