Testing queue: 5 submissions open, 23 awaiting dispatch.
#coa-reading 2025-06-07
Saturday29 messages6 participantstimes are UTC
Highlights from this day
- VialBot — Testing queue: 5 submissions open, 23 awaiting dispatch. 21:00
- pbs_pip — i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019, someone check my working 21:12
- truncation_tru — the paperwork can be perfect and the vial can still be light. weigh it 21:44
- pbs_pip — a certificate should name the method, the instrument, the column and the operator. most name none of those 22:11
one decimal versus two is usually just house style, not precision
if you only read one line on a certificate, read the lot number. if you read two, read the assay
purity is not assay
coming back to this why would a vial be 98.6 pure and still assay under label
tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the mass balance, someone check my working
i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019, someone check my working
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single wavelength detection can miss a co-eluting impurity that does not absorb there
no lot no certificate
21:25marrow.mod pinned a message
sterility and endotoxin are separate tests and almost nobody runs either on research material
[edited]is sterility tested as part of a normal purity certificate
net not gross
does anyone keep a folder of certificates to compare over time
the paperwork can be perfect and the vial can still be light. weigh it
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no lot number on this certificate, does that make it worthless
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water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it, we shall see
a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists, take that with a pinch of salt
certificate is dated before the lot date, is that just sloppiness
not evidence on its own
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a certificate should name the method, the instrument, the column and the operator. most name none of those
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22:12marrow.mod pinned a message to this channel
gross mass on a jewellery scale plus the water content is enough to catch most underfills
if you only read one line on a certificate, read the lot number. if you read two, read the assay
check the lot
two certificates from the same supplier have an identical chromatogram, is that normal
the certificate from JEEP is the one i use to teach this because it actually has a populated impurity table
does purity by hplc at one wavelength miss things
the retention time on this one is different from the last lot, problem
sloppy not sinister
for the archive update from 4 months ago: started asking every supplier for water content and about half now include it
purity is what fraction of the contents is the target. assay is how many mg are actually there. different questions