three years of water content threads, summarised so you do not have to read them
Posting this as a discussion rather than a claim: three years of water content threads, summarised so you do not have to read them. Why the same vial can honestly produce three different numbers. Purity by area percent is relative to what the detector saw on one gradient at one wavelength. Net peptide content…
Not quite. Two labs with different gradients can resolve a close-eluting impurity differently and both be reporting honestly.
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Did you get the chromatogram or only the summary line?
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.
a total of 0.4% tells you less than four named impurities adding to 0.6%
Agreed on asking for the storage condition. It is one line and it changes how you read the entire stability claim.
Did you ask for the batch-specific document, or is this the catalogue one?
Water content 3.8%, acetate 6.2%, purity 99%, net peptide about 90% of label weight. All four numbers honest, and I had to read it twice.
Cosigning. The batch identifier is load-bearing, and a certificate that cannot be tied to the vial in your hand is not about your vial.
Not quite.
This is the sentence to take away. The rest of the thread is footnotes to it.
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
net peptide content and purity are two different numbers on the same vial