Follow-up: Reconciling a label claim with a content assay

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.

I looked this up rather than remembered it, which is the right order.

Water content by Karl Fischer is worth having on a lyophilised product because residual water is both a mass contributor and a stability factor.

Reading it again, the caveat matters more than the finding.

Reconciling a label claim has been discussed here with more heat than it deserves, mostly because two definitions have been in play the whole time.

Narrowing post #25, because the general version has more than one answer.

Two claims get bundled together under Reconciling a label claim and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.

Almost every disagreement in threads like this one dissolves once you say which of the two you are making.

Coming back to post #25, 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.

It is a small point and it changes the answer, which is an awkward combination.