Expert Review Panel for Dietary Supplements

4. Based on the supporting information, is the method written clearly and concisely? If no, please specify the needed revisions.

Some clarifications suggested as follows:

C.h. -->Recommend some additional guidance on choice of trypsin. Current lack of specificity could lead to reproducibility problems.

D.i. -->Should nitrogen conversion factors be listed for the sake of consistency? In other words, how is the amount of protein being defined if the intent is to incorporate equal portions? Also, should the total Kjeldahl protein listed in this section be 19.79% instead of 79.16%? Four equal parts with the same average would then equal a total of the same value.

E.d.-->Suggest listing the set temperature here.

E.n.--> Long incubation time, is this truly needed?

F.a. --> Column listed does not match column listed in section B.c. Which is the correct column?

Table 2017.B --> Is metaline supposed to be melamine?

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?

For the samples tested this method appears to exceed the POI limits outlined in the SMPR. The type of prep used in well known in proteomic analysis therefore many labs will be able to execute this method.

Depending on interpretation the data presented may not meet the SMPR requirements for replication.

7. Any general comments about the method?

The method document could benefit from a few clarifications (column choice, trypsin recommendation, etc.).

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.

I do recommend this method for first action status if the author agrees to fill in the current gaps to the SMPR (did not test against peptides as per Table 2, and potentially insufficient replication relative to Table 3 of the SMPR).