the paperwork can be perfect and the vial can still be light. weigh it
Thread · #coa-reading · 2025-11-10
update from 3 months ago: started asking every supplier
Spun off from a message in #coa-reading on 2025-11-10. 12 messages, 4 participants.
The message this came from
- logrotate — update from 3 months ago: started asking every supplier for water content and about half now include it 18:40
whats the minimum a certificate has to have before you take it seriously
the certificate from QST is the one i use to teach this because it actually has a populated impurity table
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how do you verify a certificate is actually from the lab it says
water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it
whats the minimum a certificate has to have before you take it seriously
single wavelength detection can miss a co-eluting impurity that does not absorb there
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the retention time on this one is different from the last lot, problem
if you only read one line on a certificate, read the lot number. if you read two, read the assay
if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
is there a standard layout or does every lab do their own
sloppy not sinister
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