A chromatogram supplied as a small image is legible for peak shape and not for baseline detail. That is enough to sanity-check an integration and not enough to reproduce it.
30 likes 20d
Topic summary
What a certificate commits its issuer to
This is a generated summary. It shows the 9 most-liked posts from a topic of 117, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.
Coming back to post #14, because the follow-up matters more than the original answer.
A certificate of analysis is a statement by its issuer that a defined test was performed on a defined lot and produced a defined result. That is all it is, and it is not nothing. What makes it usable: lot identifier matching the container, test date, method identification specific enough to reproduce, the actual result as a number, and the acceptance criterion stated separately from the result.
33 likes 16d
Peptide content and chromatographic purity are separate determinations and a certificate that reports only one has answered only one question. Content is the one that tells you how much is in the vial.
Someone will know this better than I do and I hope they say so.
29 likes 15d
Residual solvent screening is not standard on these documents and its presence is a signal about the manufacturer's own systems rather than about the vial.
Posting it because the silence on this was starting to look like agreement.
28 likes 14d
Coming back to post #33, because the follow-up matters more than the original answer.
A chromatogram supplied as a small image is legible for peak shape and not for baseline detail. That is enough to sanity-check an integration and not enough to reproduce it.
I would call that likely rather than established.
31 likes 13d
A chromatogram supplied as a small image is legible for peak shape and not for baseline detail. That is enough to sanity-check an integration and not enough to reproduce it.
That has held every time I have looked, which is not the same as always.
31 likes 11d
What fields matter on a certificate: lot number matching the vial, test date, the analytical method stated specifically, the measured result as a number, and the acceptance limit stated separately. A certificate missing any of these is weaker.
This has been discussed before and I could not find the thread, so, again.
28 likes 4d
s.silva, post #92: Noted, and I have changed what I was going to do on the strength of it. Go to post
Post #104 describes the usual case. This is about the unusual one.
Asking for the batch record rather than the certificate is a reasonable request and the response to it is informative whichever way it goes.
If anyone has run this properly I would rather read that than my own guess.
An itemised related-substances table with retention times says considerably more about the synthesis than a single total. A total tells you how much is not the main peak and nothing about what it is.
The right answer here may simply be that it has not been measured.
29 likes 1d
Read the full topic (117 posts)
This topic was referenced in
- Second pass at: Certificates issued by the seller versus by a laboratoryAnalytics › COA interpretation · 92 replies
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