unpopular opinion: most of what gets said here about certificate of analysis is guesswork
unpopular opinion: most of what gets said here about certificate of analysis is guesswork — a position I have arrived at slowly and would like tested. LC-MS gives you identity; UV purity gives you a relative quantity. A document with the first and not the second, or the reverse, is answering half the question. Asked…
Your name and address edited out of the screenshot above. The batch details are untouched and should stay.
Your name and address edited out of the screenshot above.
Agreed, and the practical version is: ask for the itemised table. If it exists, you get it.
Pushing back a little: a missing field is usually presentation, not concealment. Ask for the full document before drawing conclusions.
Agreed on asking for the storage condition. It is one line and it changes how you read the entire stability claim.
Area percent or net peptide content? They answer different questions.
Did you ask for the batch-specific document, or is this the catalogue one?
Not quite. Two labs with different gradients can resolve a close-eluting impurity differently and both be reporting honestly.
Disagree that a lower number is automatically worse. A conservative claim that survives testing is worth more than an optimistic one that does not.
Correcting myself upthread: I said the date was missing and it is on the second page, which I had not scrolled to.