#coa-reading 2026-01-23

retention time shifts between runs are normal. relative retention time is the number to compare

net not gross

Purity check: no report on file for lot B-0114. Nothing logged either way.

not detected means nothing

update from 1 months ago: started asking every supplier for water content and about half now include it

is area percent the same thing as how many mg are in the vial

i asked JEEP for the method and they sent it. that alone put them ahead of most

why do some certificates report to one decimal and some to two

nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself

why would a vial be 99 pure and still assay under label

residual solvents matter more than people think for anything that went through a lot of purification steps

genuine question should a certificate say which instrument and method they used

same chromatogram

tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the mass balance

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

no lot number, no certificate. a document you cannot tie to the vial in your hand is decoration

the paperwork can be perfect and the vial can still be light. weigh it

follow up water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it

sterility and endotoxin are separate tests and almost nobody runs either on research material

single wavelength detection can miss a co-eluting impurity that does not absorb there, still working it out

unrelated but the related substances table is the interesting part. a row of "not detected" means they did not look hard

looks re-dated

ok so a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully

i have never seen a research certificate with an endotoxin result on it. not once

good certificate actually

thats a tell

one decimal versus two is usually just house style, not precision

is sterility tested as part of a normal purity certificate

test it yourself

gross mass on a jewellery scale plus the water content is enough to catch most underfills

not evidence on its own

is endotoxin ever tested on research material

ask for water content

if you only read one line on a certificate, read the lot number. if you read two, read the assay

the font on this one changes halfway down, am i being paranoid

tfa or acetate, how do i tell from the paperwork