help me understand area percent, I have read the wiki twice
help me understand area percent, I have read the wiki twice. If this has been answered properly somewhere, link me and I will delete. How to ask for a batch record without it turning into a negotiation. One email, three requests: the batch-specific certificate for lot X, the method line behind it, and the storage…
ask for the storage condition the stability statement was written against
ask for the storage condition the stability statement was written against
Adding the bit that always gets missed: the lot on the vial has to match the lot on the page, or none of this applies to your material.
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
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Correction: that is net peptide content, not purity. Different number, different meaning, and the document says so if you read the row label.
The PDF creation date being later than the analysis date is usually a re-issue or a re-export. It is worth one question and it is not evidence of anything on its own.
Yes. The structure of the document matters at least as much as the number printed on it.
the related substances line is where the story is
a certificate with no method line is decorative
Batch number and date of analysis, are both on there?
UV at 214nm sees the peptide bond and picks up almost everything; at 280nm you are looking at aromatics only. Which wavelength the number came from is part of the number.
Started keeping a folder of every certificate I have been sent. The ones that itemise impurities are a small group and they are mostly the same suppliers.