the related substances table is the interesting part. a row of "not detected" means they did not look hard
#coa-reading 2026-05-01
Friday21 messages4 participantstimes are UTC
Highlights from this day
- karl_fischer — no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration, take that with a pinch of salt 22:19
- HPLC_Hank — why do some certificates report to one decimal and some to two a supplier certificate on its own is a starting point, not evidence. that is the whole reason the… 22:49
- HPLC_Hank — quick one i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does 22:50
- plus_sixteen — retention time shifts between runs are normal. relative retention time is the number to compare 22:51
is there a standard layout or does every lab do their own
thats a real table
if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
*PeptideMeter not the other one
no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration, take that with a pinch of salt
the three way match is vial, certificate, invoice. if all three agree you have something
the retention time on this one is different from the last lot, problem
how do you verify a certificate is actually from the lab it says
[edited]not detected means nothing
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no lot number on this certificate, does that make it worthless
why do some certificates report to one decimal and some to two
a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists
quick one i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
retention time shifts between runs are normal. relative retention time is the number to compare
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purity is not assay
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should a certificate say which instrument and method they used
the font on this one changes halfway down, am i being paranoid
test it yourself
thats the counterion
slightly off topic but tfa or acetate, how do i tell from the paperwork
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