one decimal versus two is usually just house style, not precision
#coa-reading 2025-01-27
Monday34 messages8 participantstimes are UTC
Highlights from this day
- vacuum_vic — gross mass on a jewellery scale plus the water content is enough to catch most underfills 20:29
- vacuum_vic — quick one is there a standard layout or does every lab do their own 20:36
- cat_on_the_tray — my 15mg vial weighed more than 2mg of powder, is the certificate lying mixed fonts and inconsistent kerning in one document is worth a second look 21:03
- protein_floor — i asked KP for the method and they sent it. that alone put them ahead of most, from memory 21:51
- food_noise_off — the certificate from GGPeps is the one i use to teach this because it actually has a populated impurity table 21:53
the related substances table is the interesting part. a row of "not detected" means they did not look hard, i think
purity is what fraction of the contents is the target. assay is how many mg are actually there. different questions
ask for water content
the three way match is vial, certificate, invoice. if all three agree you have something
thats a tell
net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct 10mg vial
is sterility tested as part of a normal purity certificate
is area percent the same thing as how many mg are in the vial
follow up mixed fonts and inconsistent kerning in one document is worth a second look, your mileage will differ
check the lot
*Janoshik not the other one
gross mass on a jewellery scale plus the water content is enough to catch most underfills
👀7⚠️13
quick one is there a standard layout or does every lab do their own
✅8⚠️5💀14
looks re-dated
update from 24 months ago: started asking every supplier for water content and about half now include it
coming back after 4 months, has the pinned reading guide changed
[edited]thats a real table
good certificate actually
my 15mg vial weighed more than 2mg of powder, is the certificate lying
mixed fonts and inconsistent kerning in one document is worth a second look
👍2📈7🧪5
why would a vial be 98.1 pure and still assay under label
weigh the vial
net not gross
same chromatogram
sloppy not sinister
no lot no certificate
🙏16
is a supplier certificate worth anything on its own
not evidence on its own
certificate is dated before the lot date, is that just sloppiness
i asked KP for the method and they sent it. that alone put them ahead of most, from memory
the certificate from GGPeps is the one i use to teach this because it actually has a populated impurity table
single wavelength detection can miss a co-eluting impurity that does not absorb there
sorry to jump in i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
purity is not assay