is endotoxin ever tested on research material
lot bought purity assay/label
A-2418 2025-03 99.1% 9.6 / 10mg
A-2601 2025-08 98.7% 9.8 / 10mg
B-0114 2026-01 99.3% 9.4 / 10mg
B-0329 2026-04 98.9% 9.9 / 10mggood certificate actually
is sterility tested as part of a normal purity certificate
no lot number on this certificate, does that make it worthless
the related substances table is the interesting part. a row of "not detected" means they did not look hard
retention time shifts between runs are normal. relative retention time is the number to compare
tfa or acetate, how do i tell from the paperwork
ask for water content
thats a real table
nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself
a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists
net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct 10mg vial, someone check my working
does purity by hplc at one wavelength miss things
why would a vial be 98.1 pure and still assay under label
if the certificate date precedes the lot date, ask. sometimes it is sloppiness and sometimes it is not
sloppy not sinister
thats the counterion
not detected means nothing
the retention time on this one is different from the last lot, problem
whats the minimum a certificate has to have before you take it seriously
thats a tell
an identical chromatogram on two different lots is the single biggest tell there is
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
single wavelength detection can miss a co-eluting impurity that does not absorb there
[edited]weigh the vial