Coming back to: Batch date after test date, and other internal inconsistencies

On the subject in the title: Batch date after test date, and other internal inconsistencies Working notes rather than a conclusion.

Batch date — I have the observation and I do not trust my interpretation of it, so I am posting the observation and holding the interpretation back.

Numbers, method and the conditions under which they were collected are below. Interpret them however they warrant.

Nobody has said the unglamorous part of Batch date yet, so: most of the variation is explained by things that are boring to write about and easy to check.

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.

None of the above is medical advice and I am not qualified to give any.

This is the first time the answer has come with its own limits attached. Appreciated.

Reading back through the Batch date threads from last year, the same three questions come up every time and only one of them has ever been answered properly. That seems like a documentation gap rather than a knowledge gap.

Batch date is well covered in the tag pages, and the older discussions are better than the recent ones because they were argued out properly. Worth twenty minutes before adding to this one.

This follows post #6 rather than contradicting it.

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 claim is narrower than it sounds, and deliberately so.

Worth separating two things that post #5 runs together.

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.

Adding it because I spent an afternoon working it out and nobody should have to twice.

The signature block matters more than it appears to. A named individual with a date is a different kind of document from an unsigned one, whatever the numbers say.

Post #8 put the caveat in the right place and I want to underline it.

If someone has run Batch date properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.

I read post #7 twice before replying, because I had assumed the opposite.

Counterpoint on Batch date, offered without confidence: the same observation is consistent with a much duller explanation, and nobody has ruled the dull one out.

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.

Since Batch date keeps coming up, it should probably be a maintained page rather than a recurring thread. I am happy to draft it if someone with more direct experience will review it.

Asking for the batch record rather than the certificate is a reasonable request and the response to it is informative whichever way it goes.