why does nobody talk about batch
Slightly embarrassed to be asking this, but: why does nobody talk about batch.
Spent four months confusing area% and mass% in every post I made here. One explainer thread and it clicked permanently.
Water content 3.8%, acetate 6.2%, purity 99%, net peptide about 90% of label weight. All four numbers honest, and I had to read it twice.
The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary.
Happy to answer the boring questions. Those are usually the ones worth asking.
best — the order this archive was captured in
Area percent is the peak area of your compound over the total integrated area, at one wavelength, on one gradient. It is a relative measure of what the detector saw, not a mass fraction of the vial.
Does the lot on the vial match the lot on the page?
ask for the storage condition the stability statement was written against
Reminder: a question about a document is not an accusation about a supplier, and posts that blur the two get retitled.
My first certificate had a compound name, a percentage and a logo. I thought that was normal. It is not, and now I know what to ask for.
Sent one vial to PeptideMeter and PeptideMeter. 98.8% and a claimed 98.0%. Cost me more than the vial and I would do it again.
Correction: that is net peptide content, not purity. Different number, different meaning, and the document says so if you read the row label.
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.