Knowledge and sourcing
Quality and testing
What analysis can tell you, and what it cannot.
This circle is the technical companion to the sourcing circle. It is about the analysis itself: what HPLC measures, what mass spectrometry confirms, why an endotoxin panel is a different question from purity, and the uncomfortable fact that a good number on a document tells you about the sample that was tested and not about the vial in your fridge.
Several members are chemists and they correct the facilitator regularly, which is how it should work.
Who this circle is for
- You want to understand the analytical methods
- You have had material independently tested
- You work in analytical chemistry and can explain things
Agreements here
- Technical claims get a method attached or they get questioned
- No test result is used to endorse a supplier
What HPLC actually measures
Zeb12 replies
Starting a thread on this because it keeps coming up in ones and twos: What HPLC actually measures Putting this here because I do not want to be sold anything, I want to know what is…
A chemist explains why "99 per cent" is not a grade
Wystan12 replies
A question rather than an update: A chemist explains why "99 per cent" is not a grade Putting this here because I do not want to be sold anything, I want to know what is actually…
Why I no longer trust a certificate I did not commission
Wystan17 replies
Why I no longer trust a certificate I did not commission — putting it in its own thread so it does not get lost in the check-in. Evidence question. I would rather have an honest "we do not…
Medutest and VendorInvestigate — different methods, different purposes
Nadja20 replies
Medutest and VendorInvestigate — different methods, different purposes Writing it down partly to work out what I actually think. Evidence question. I would rather have an honest "we do not…
Peptide mapping and impurity profiles
Holly15 replies
Something I have been sitting with: Peptide mapping and impurity profiles Not looking for advice so much as other people's experience. Putting this here because I do not want to be sold…
Mass spectrometry confirms identity, not quality
Tobias13 replies
Something I have been sitting with: Mass spectrometry confirms identity, not quality Not looking for advice so much as other people's experience. Evidence question. I would rather have an…
Endotoxin testing is a different question entirely
Hetty16 replies
A question rather than an update: Endotoxin testing is a different question entirely Putting this here because I do not want to be sold anything, I want to know what is actually…
Reading a chromatogram for the first time
Dara22 replies
Starting a thread on this because it keeps coming up in ones and twos: Reading a chromatogram for the first time I have read the paper and I am not sure I have understood it. My prescriber…
Sterility, pyrogens and the limits of a purity panel
Gwynfor16 replies
Starting a thread on this because it keeps coming up in ones and twos: Sterility, pyrogens and the limits of a purity panel Putting this here because I do not want to be sold anything, I…
PeptideMeter publishing the unflattering results
Hetty16 replies
PeptideMeter publishing the unflattering results Writing it down partly to work out what I actually think. Evidence question. I would rather have an honest "we do not know" than a…
Why two labs can report different numbers on the same sample
Dara15 replies
Why two labs can report different numbers on the same sample — putting it in its own thread so it does not get lost in the check-in. Putting this here because I do not want to be sold…
What Janoshik reports and what it does not claim
Yannick20 replies
Starting a thread on this because it keeps coming up in ones and twos: What Janoshik reports and what it does not claim I have read the paper and I am not sure I have understood it. I have…
Water content and why it changes the arithmetic
Hetty21 replies
A question rather than an update: Water content and why it changes the arithmetic I have read the paper and I am not sure I have understood it. I have read the guides here, which were more…
What a reference standard is for
Zeb16 replies
Something I have been sitting with: What a reference standard is for Not looking for advice so much as other people's experience. I have read the paper and I am not sure I have understood…