What a certificate commits its issuer to posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
That is the distinction I keep failing to hold on to. Written down now.
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.
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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 is the version I use. It may not be the version that is correct.
Post #63 put the caveat in the right place and I want to underline 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 answer changed when I changed how I was measuring, which was informative.
Reading old certificates: if a certificate is dated years ago, the lot it describes might be old. That is not automatically a problem but it is worth noting. Fresh testing on the current lot is stronger than old testing on an older lot.
I read post #67 twice before replying, because I had assumed the opposite.
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".
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.
Post #70 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.
That is the practical version. The rigorous version is longer and says the same thing.
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Asking for the batch record rather than the certificate is a reasonable request and the response to it is informative whichever way it goes.
I would hold that lightly until someone with a larger sample weighs in.
Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported.
Worth separating two things that post #73 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".
Scoping that to what I have actually seen rather than what I have read.
Narrowing post #74, because the general version has more than one answer.
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.
That is my reading. Someone else read the same page differently and was reasonable.
Everything in post #73 holds. The case it does not cover is the one I have.
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.
Worth checking against a second source before it gets quoted onward.
That is clearer than the version I had in my head. Thank you.
"Not less than 98 per cent" is a specification. "98.3 per cent" is a result. A certificate carrying only the first has not told you what was measured.
I had written a reply contradicting post #76 and deleted it. Here is what survived.
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 claim is narrower than it sounds, and deliberately so.
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I had written a reply contradicting post #78 and deleted it. Here is what survived.
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.
Confirming post #80 from a second method, which matters more than confirming it from a second person.
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.
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.
If that is already documented somewhere, ignore me and link 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 this contradicts something upthread, the upthread version may well be the better one.
Post #85 is right about the mechanism and I think understates the practical bit.
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.
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.
This is the first time the answer has come with its own limits attached. Appreciated.
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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.
Filing this under things that are true until someone shows me otherwise.