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4. Based on the supporting
information, is the method
written clearly and concisely?
If no, please specify the
needed revisions.
The method is written very clearly. Given the detail included regarding method
development and validation, I would not consider the submission package concise.
However, the method details could be extracted into a concise stand-alone document.
5. Based on the supporting
information, what are the
pros/strengths of the
method?
The supporting information includes extensive method development and validation
data, in some cases exceeded the expectation of the SMPR. This additional data
added significant amount of credibility to the method. The method demonstrates strong
performance with a number of certified standards.
6. Based on the supporting
information, what are the
cons/weaknesses of the
method?
The majority of the method validation was performed with a tea blank that is not true
kombucha. Certified standards were analyzed in water and a beer standard was also
used, both of which performed well. Limited validation of the method was performed
with actual kombucha. Based on the method development, one would expect the
method to perform equally across the matrices, however it was not explicitly
demonstrated.
7. Any general comments
about the method?
A GC-MS approach is highly suitable for the quantitation of ethanol in beverages. This
method demonstrates thorough development and optimization for quantitation of
ethanol in liquid samples. It is weaker with regard to validation in kombucha matrix, but
has potential to be highly applicable and meet all requirements.
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.
Yes, I recommend this method to be adopted as a First Action. The SPME-GC-MS
technology is highly suitable for the analysis of ethanol in kombucha, and I believe that
additional inter-laboratory validation will prove its performance. Not all Method
Performance Requirements were determined in a kombucha matrix or in the same
vocabulary as the SMPR, but the method appears to meet nearly all requirements.
Recommendation for the Method