how do you verify a certificate is actually from the lab it says
#coa-reading 2026-02-17
Tuesday13 messages2 participantstimes are UTC
Highlights from this day
- amylin_amy — why do some certificates report to one decimal and some to two purity is what fraction of the contents is the target. assay is how many mg are actually there.… 13:38
- amylin_amy — single wavelength detection can miss a co-eluting impurity that does not absorb there 13:41
- amylin_amy — the certificate from SWB is the one i use to teach this because it actually has a populated impurity table, your mileage will differ 13:45
- amylin_amy — sterility and endotoxin are separate tests and almost nobody runs either on research material 13:49
follow up retention time shifts between runs are normal. relative retention time is the number to compare, thats just me
why do some certificates report to one decimal and some to two
purity is what fraction of the contents is the target. assay is how many mg are actually there. different questions
good certificate actually
an identical chromatogram on two different lots is the single biggest tell there is
single wavelength detection can miss a co-eluting impurity that does not absorb there
| Line | Claims | Does not claim |
|---|---|---|
| Purity (area %) | fraction of detected material that is the target | how many mg are in the vial |
| Assay / content | mg of target per vial | that it is sterile |
| Water content | mass fraction that is water | anything about purity |
| Counterion | salt form and its mass share | net peptide unless stated |
| Related substances | what else was seen | what was not looked for |
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ok so certificate is dated before the lot date, is that just sloppiness
the certificate from SWB is the one i use to teach this because it actually has a populated impurity table, your mileage will differ
check the lot
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*Janoshik not the other one
sterility and endotoxin are separate tests and almost nobody runs either on research material
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no lot number on this certificate, does that make it worthless
right so is water content normally on a certificate or do you have to ask