i keep every certificate in a dated folder and compare them

teaching example again i keep every certificate as a pdf named lot-vendor-date. searchable and it has saved me twice

harder to fake

less good news i keep every certificate as a pdf in a folder by year and it has settled three arguments in two years, email before accusation

good certs are checkable

not absence

document question not a chemistry one a re-dated certificate is usually laziness rather than fraud, and it still means you cannot check the story

the teaching example we use is the one with the populated impurities table and the dated signature

nobody can authenticate a certificate from a scan. you authenticate the material by testing it yourself, karl fischer would settle it

i had a certificate and an independent assay on the same lot come out within half a percent, which was reassuring, ask for the batch record

a jpeg of a certificate is not automatically fake and it is automatically harder to check

a supplier certificate on its own is a starting point, not evidence. that is the whole reason the verification channel exists

not detected is a statement about the detection limit and nothing else, and it gets read as absence far too often, signed and dated or it is half a document

batch record instead this time the three way match is vial, certificate, invoice. if all three agree you have something, not detected means the limit

asked for karl fischer, so related substances itemised by name beats a total percentage every time