is water content normally on a certificate or do you have to ask
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#coa-reading 2026-02-14
Saturday13 messages4 participantstimes are UTC
Highlights from this day
net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct 10mg vial
an identical chromatogram on two different lots is the single biggest tell there is
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i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019
gross mass on a jewellery scale plus the water content is enough to catch most underfills
[edited]weigh the vial
net not gross
a vial can be 99.4% pure and hold 8.1mg of a 10mg label. both numbers are true and only one of them is the one you care about
whats the related substances table actually telling me
same chromatogram
Inter-lab diff for lot F-1330: 98.6% vs 99%. Within expected range.
the three way match is vial, certificate, invoice. if all three agree you have something, your mileage will differ
coming back to this mixed fonts and inconsistent kerning in one document is worth a second look