[Suspicious] the same signature image on COAs from three vendors
the same signature image on COAs from three vendors. Multiple orders, one buyer, which makes this a series and not a survey.
Ask what the stability statement was written against — temperature, light, and whether it was the lyophilised powder or the reconstituted solution. Those are three different claims.
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rather than its size.
UV at 214nm sees the peptide bond and picks up almost everything; at 280nm you are looking at aromatics only. Which wavelength the number came from is part of the number.
I will update this if the picture changes rather than quietly leaving it up.
best — the order this archive was captured in
Net peptide content is the fraction of the powder that is actually peptide once counterion, water and residual solvent are accounted for. A 99% pure acetate salt can still be about 85% peptide by mass.
Careful — "the metadata looks odd" is a reason to ask a question, not a conclusion. Re-issues are ordinary.
net peptide content and purity are two different numbers on the same vial
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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.
Correction: that is net peptide content, not purity. Different number, different meaning, and the document says so if you read the row label.
- 1Net peptide content is the fraction of the powder that is actually peptide…6 comments in this branch · started by u/ahmed_rasmussen