is water content normally on a certificate or do you have to ask
#coa-reading 2025-12-17
Wednesday15 messages5 participantstimes are UTC
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net not gross
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net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct 10mg vial
i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019
one decimal versus two is usually just house style, not precision, take that with a pinch of salt
coming back to this water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it
update on the earlier thing an identical chromatogram on two different lots is the single biggest tell there is
i asked Homopeptide for the method and they sent it. that alone put them ahead of most
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nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself
two certificates from the same supplier have an identical chromatogram, is that normal
whats the related substances table actually telling me
why would a vial be 98.1 pure and still assay under label
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purity is not assay
check the lot
if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not, ymmv