thats a real table
#coa-reading 2025-04-28
Monday24 messages6 participantstimes are UTC
Highlights from this day
- the_bet_2026 — the related substances table is the interesting part. a row of "not detected" means they did not look hard 12:36
- LC_MS_Lena — why do some certificates report to one decimal and some to two 13:16
- LC_MS_Lena — 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 13:31
- see_a_clinician — a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists 14:05
- the_bet_2026 — does anyone keep a folder of certificates to compare over time an identical chromatogram on two different lots is the single biggest tell there is 15:28
net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct 10mg vial
same chromatogram
the related substances table is the interesting part. a row of "not detected" means they did not look hard
🎉11📈4❤️6
the retention time on this one is different from the last lot, problem
one decimal versus two is usually just house style, not precision
not detected means nothing
why do some certificates report to one decimal and some to two
👀8
sloppy not sinister
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
thats the counterion
net not gross
[edited]no lot no certificate
✅9❤️11⚠️10
is water content normally on a certificate or do you have to ask
the paperwork can be perfect and the vial can still be light. weigh it
for the archive should a certificate say which instrument and method they used
update on the earlier thing is area percent the same thing as how many mg are in the vial
good certificate actually
[edited]a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists
the honest summary is that a certificate tells you what the supplier says about a lot they chose to test
not evidence on its own
test it yourself
looks re-dated
does anyone keep a folder of certificates to compare over time
an identical chromatogram on two different lots is the single biggest tell there is