[Lab] split one vial across Janoshik and Medutest — 95.1% and 97.6%
split one vial across Janoshik and Medutest — 95.1% and 97.6%. I will put the method line and the batch identifier up front because that is what makes this checkable.
95.1% and 97.6%. Those are measured, not estimated, and not rounded up in my favour.
The PDF creation date being later than the analysis date is usually a re-issue or a re-export. It is worth one question and it is not evidence of anything on its own.
Asked FGP for the batch-specific certificate and had the full document — batch, date, method line naming the column — inside six hours. That is now my baseline for everybody.
Not medical advice, obviously, and nothing here is approved for human use. One person with a spreadsheet.
best — the order this archive was captured in
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.
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.
Cosigning. The batch identifier is load-bearing, and a certificate that cannot be tied to the vial in your hand is not about your vial.
Are the related substances itemised or is it a single total?
area% is not mass%, and the difference is the whole game
Batch number and date of analysis, are both on there?
Your name and address edited out of the screenshot above. The batch details are untouched and should stay.
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Did you get the chromatogram or only the summary line?
Did you get the chromatogram or only the summary line?
Agreed, and the practical version is: ask for the itemised table. If it exists, you get it.
Same view. Homopeptide prints the column and the gradient, which means somebody could actually reproduce the run.
Disagree that a lower number is automatically worse. A conservative claim that survives testing is worth more than an optimistic one that does not.
Disagree that a lower number is automatically worse.
Adding the bit that always gets missed: the lot on the vial has to match the lot on the page, or none of this applies to your material.
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.
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.
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rathe
This is the sentence to take away. The rest of the thread is footnotes to it.
What does the method line actually say? Not the technique — the column and the gradient.
Area percent or net peptide content? They answer different questions.
identity and quantity are two questions and most documents answer one
- 1Your name and address edited out of the screenshot above. The batch details…8 comments in this branch · started by u/certified_reference
- 2LC-MS gives you identity; UV purity gives you a relative quantity. A…6 comments in this branch · started by u/kavya_verhoeven