the retention time on this one is different from the last lot, problem
#coa-reading 2025-02-14
Friday28 messages7 participantstimes are UTC
Highlights from this day
- lot_number_lou — water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it 09:29
- endotoxin_ed — sterility and endotoxin are separate tests and almost nobody runs either on research material, still working it out mixed fonts and inconsistent kerning in one… 10:01
- endotoxin_ed — a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully 10:03
- endotoxin_ed — i asked KP for the method and they sent it. that alone put them ahead of most 12:17
- salt_bridge — an identical chromatogram on two different lots is the single biggest tell there is 13:21
no lot no certificate
i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019
same chromatogram
thats a real table
one decimal versus two is usually just house style, not precision
water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it
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sterility and endotoxin are separate tests and almost nobody runs either on research material, still working it out
mixed fonts and inconsistent kerning in one document is worth a second look
a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully
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check the lot
update from 3 months ago: started asking every supplier for water content and about half now include it, thats just me
what does net peptide content mean next to gross mass
sloppy not sinister
update on the earlier thing nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself
[edited]good certificate actually
i asked KP for the method and they sent it. that alone put them ahead of most
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mixed fonts and inconsistent kerning in one document is worth a second look
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is area percent the same thing as how many mg are in the vial
the honest summary is that a certificate tells you what the supplier says about a lot they chose to test
residual solvents matter more than people think for anything that went through a lot of purification steps
not evidence on its own
[edited]looks re-dated
no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration, thats just me
[edited]net not gross
not detected means nothing
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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
is a supplier certificate worth anything on its own
the paperwork can be perfect and the vial can still be light. weigh it
an identical chromatogram on two different lots is the single biggest tell there is
coa-sg-1177.pdf
1 page · 391 KB · not retained in the public archive
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