"Greater than or equal to 99%" as a specification rather than a result posts 31–60
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
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.
The general case is well covered; this is the awkward specific one.
Adding the measurement that post #32 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".
The right answer here may simply be that it has not been measured.
Post #30 describes the usual case. This is about the unusual one.
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.
If anyone can point at the primary source I would be grateful.
Post #34 put the caveat in the right place and I want to underline it.
A certificate 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.
I would want the raw data before agreeing with my own summary of it.
Post #36 is right about the mechanism and I think understates the practical bit.
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.
Written in the hope of being told what I have missed.
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 #39 answers the question as asked. The question underneath it is different.
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.
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".
If that reads as pedantic, it is, and it has saved me twice.
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.
A modest claim, modestly supported.
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.
It is one reading of the data and not the only reasonable one.
That reframing is the whole thing. The facts I already had.
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".
Small point, but it is the one that usually catches people.
Answering the question post #48 raises rather than the one it answers.
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.
Adding a source would improve this post and I do not have one to hand.
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.
Not disagreeing with anyone above, just adding the bit I keep having to look up.
Building on post #50 rather than restating 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".
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 said this before in a thread nobody could find, so it is worth repeating.
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.
Posted with less confidence than the sentence structure implies.
Taking post #53 at face value and following it one step further.
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.
Collapsed as off-topic by two members at trust level 3 or above
Post #52 and I disagree about the size of the effect, not about the direction.
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".
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.
Old habit: I write down the expected answer before I calculate it.
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.
It cost nothing to check and would have cost something not to.
Worth separating two things that post #57 runs together.
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".
This is the sort of thing that ought to be settled and apparently is not.