"Greater than or equal to 99%" as a specification rather than a result

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.

Post #12 and I disagree about the size of the effect, not about the direction.

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.

Marking my place. If it changes for me I will come back and say so.

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.

The mechanism is plausible, which is not the same as established.

Adding the measurement that post #18 says would settle it.

The distinction between release testing and characterisation is one industrial documents make and retail ones usually do not. It is the difference between "we tested every lot for this" and "we established this once".

Post #16 describes the usual case. This is about the unusual one.

When a document puts the specification in the result column, it has told you the release criterion, not the measurement. Those are different claims and the second is weaker.

It is the kind of thing that is obvious once and never again.

The distinction between release testing and characterisation is one industrial documents make and retail ones usually do not. It is the difference between "we tested every lot for this" and "we established this once".

I checked the source rather than the summary, and they differ.

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.

On post #21 — agreed on the reasoning, with one qualification.

The fields that make one usable: lot identifier matching the container, test date, method identification specific enough to reproduce, the result as a number, and the acceptance criterion stated separately from the result.

Useful. I had the fact and not the reason, which turns out to be the important half.

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 have seen it go both ways, which is why I hedge.

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.

Adding the measurement that post #25 says would settle it.

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.

Everything in post #25 holds. The case it does not cover is the one I have.

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.

One case, stated as one case.

Narrowing post #29, because the general version has more than one answer.

A document that puts the specification in the result column has told you the release criterion rather than the measurement. Those are different claims and the difference is the whole point of reading the document.

I keep a log of this specifically because memory is unreliable about it.