thats a tell
#coa-reading 2025-08-06
Wednesday26 messages6 participantstimes are UTC
Highlights from this day
- pinch_not_stretch — i asked JEEP for the method and they sent it. that alone put them ahead of most 18:27
- pinch_not_stretch — certificate is dated before the lot date, is that just sloppiness 19:10
- pinch_not_stretch — update on the earlier thing retention time shifts between runs are normal. relative retention time is the number to compare 19:29
- tb500_tobias — the certificate from SWB is the one i use to teach this because it actually has a populated impurity table 19:47
- pinch_not_stretch — the related substances table is the interesting part. a row of "not detected" means they did not look hard 19:50
thats a real table
the three way match is vial, certificate, invoice. if all three agree you have something, i have it written down somewhere
coming back after 23 months, has the pinned reading guide changed
a vial can be 99.4% pure and hold 8.1mg of a 10mg label. both numbers are true and only one of them is the one you care about
i asked JEEP for the method and they sent it. that alone put them ahead of most
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the font on this one changes halfway down, am i being paranoid
same chromatogram
certificate is dated before the lot date, is that just sloppiness
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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
is area percent the same thing as how many mg are in the vial
gross mass on a jewellery scale plus the water content is enough to catch most underfills
unrelated but if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself
i have never seen a research certificate with an endotoxin result on it. not once
i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
not evidence on its own
update on the earlier thing retention time shifts between runs are normal. relative retention time is the number to compare
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two certificates from the same supplier have an identical chromatogram, is that normal
the honest summary is that a certificate tells you what the supplier says about a lot they chose to test
what does net peptide content mean next to gross mass
how do you verify a certificate is actually from the lab it says
i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019
the certificate from SWB is the one i use to teach this because it actually has a populated impurity table
the related substances table is the interesting part. a row of "not detected" means they did not look hard
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pinch_not_stretcha supplier certificate on its own is a starting point, not evidence. that is the whole…
is a supplier certificate worth anything on its own