the retention time on this one is different from the last lot, problem
#coa-reading 2024-09-28
Saturday29 messages6 participantstimes are UTC
Highlights from this day
- half_life_hal — is area percent the same thing as how many mg are in the vial 10:33
- VialBot — Purity check: no report on file for lot B-0114. Nothing logged either way. 10:41
- cagri_curious — 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… 11:54
- tarpit_tam — for the archive the honest summary is that a certificate tells you what the supplier says about a lot they chose to test 14:36
gross mass on a jewellery scale plus the water content is enough to catch most underfills, ill dig out the number
a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists
how do you verify a certificate is actually from the lab it says
thats the counterion
ok so i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does, thats one data point
mixed fonts and inconsistent kerning in one document is worth a second look
is area percent the same thing as how many mg are in the vial
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good certificate actually
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
unrelated but no lot number on this certificate, does that make it worthless
while im here certificate is dated before the lot date, is that just sloppiness
[edited]Purity check: no report on file for lot B-0114. Nothing logged either way.
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is water content normally on a certificate or do you have to ask
a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully
single wavelength detection can miss a co-eluting impurity that does not absorb there
an identical chromatogram on two different lots is the single biggest tell there is
i keep every certificate in a dated folder and compare them. two suppliers had not changed their template since 2019, thats one data point
retention time shifts between runs are normal. relative retention time is the number to compare
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
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a certificate should name the method, the instrument, the column and the operator. most name none of those
*Janoshik not the other one
tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the mass balance, still working it out
while im here coming back after 22 months, has the pinned reading guide changed
is a supplier certificate worth anything on its own
i have never seen a research certificate with an endotoxin result on it. not once
for the archive the honest summary is that a certificate tells you what the supplier says about a lot they chose to test
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if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
is sterility tested as part of a normal purity certificate
looks re-dated