[Lab] 10th independent test on GL Biochem — 99.4% on a claimed 99.0%, and the trend is the interesting part
Posting this because the title is the whole finding — 10th independent test on GL Biochem — 99.4% on a claimed 99.0%, and the trend is the interesting part — and a number without its method is a rumour. The relevant figures are 99.4% and 99.0%, and they come from the same log I have kept the whole time.…
Net peptide content accounts for counterion, water and residual solvent. On some of these compounds the gap between purity and net content is substantial and entirely honest.
Push back: handling advice from one compound does not transfer to another just because both are peptides.
Bought small on anything without a testing history here. That rule has never once cost me anything.
For any compound with a thin testing history, identity is the first question. Mass spectrometry against a theoretical mass answers it; an area-percent purity figure does not.
Correction: that name covers two different molecules and the thread has been discussing both as one.
lyophilised and stored cold is the default for a reason
a mass spectrum costs little and answers the real question
I would not treat catalogue breadth as a quality signal. It is a business decision, not an analytical one.
That result is an area percent from an unspecified method, which is not the same as the identity confirmation being discussed.
Disagree — that name refers to at least two different molecules depending on who is selling it. The thread needs to be specific.
What storage conditions did they specify?
Which exact molecule? That name covers more than one.
the same name covers several different molecules in this space
Net peptide content on the certificate?
Yes. Naming conventions in this corner are loose enough that the same word covers several different molecules.
Asked CPC which lines they keep in regional stock versus make to order and got a clear split. It changed what I ordered.