if you only read one line on a certificate, read the lot number. if you read two, read the assay, still working it out
the related substances table is the interesting part. a row of "not detected" means they did not look hard
#coa-reading 2025-07-02
Wednesday20 messages5 participantstimes are UTC
Highlights from this day
- LC_MS_Lena — if you only read one line on a certificate, read the lot number. if you read two, read the assay, still working it out the related substances table is the interesting… 18:32
- LC_MS_Lena — no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration 18:34
- LC_MS_Lena — 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 19:19
- HPLC_Hank — for the archive if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not 19:56
- assay_low_al — the honest summary is that a certificate tells you what the supplier says about a lot they chose to test, not advice obviously 20:27
no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration
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should a certificate say which instrument and method they used
water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it
net not gross
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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
looks re-dated
is a supplier certificate worth anything on its own
sloppy not sinister
one decimal versus two is usually just house style, not precision
is sterility tested as part of a normal purity certificate
for the archive if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
test it yourself
mixed fonts and inconsistent kerning in one document is worth a second look
the honest summary is that a certificate tells you what the supplier says about a lot they chose to test, not advice obviously
single wavelength detection can miss a co-eluting impurity that does not absorb there
how do you verify a certificate is actually from the lab it says
thats the counterion
ask for water content
does purity by hplc at one wavelength miss things
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