Page 6 of 21 · 503 questions tagged hplc.
For reference: 97.9% · chromatogram. I want to understand what this actually establishes, as opposed to what it is being used to imply. My concern is that I am being…
What I am working with: 95.2% · sampling plan. I would like help reading this properly rather than being told what conclusion to reach. I have the full report…
For reference: 97.1% · survodutide. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…
This is my second independent submission on material from the same supplier. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware…
I have the report as a PDF with the chromatogram on page two, so I can quote specifics. I can do the algebra. I am not confident about the conversion factors. If…
Stated plainly: 95.2% · a C18 column · semaglutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
What I have: 98.8% · retatrutide. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would rather…
Stated plainly: 99.1% · sampling plan. I would like help reading this properly rather than being told what conclusion to reach. I have the full report including the…
A vendor sent me a report showing a clean deconvolved mass at 4113.6 for semaglutide with, in their words, "no impurity peaks detected". Their sales copy turns that…
Numbers first: 95.2% · retatrutide. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
Setup, so nobody has to ask: orforglipron · a C18 column · retatrutide. I suspect the honest answer is that it depends, in which case I would like to know on what.…
Details up front: 95.2% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear…
Setup, so nobody has to ask: 98.2% · a C18 column · ecnoglutide. I would like help reading this properly rather than being told what conclusion to reach. I have the…
For reference: an HPLC purity test · retatrutide. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me…
The case in front of me: 99.1% · a C4 column · retatrutide. I would like to know the limits of what can be inferred from this. What I am trying to avoid is…
The particulars: an HPLC purity test · retatrutide. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…
Concretely: an ammonium formate mobile phase · liraglutide · a C8 column. This is one of those things that everyone repeats and nobody derives. This matters…
The case in front of me: 96.8% · a C4 column · orforglipron. The figures are clear enough; the question is what they mean and what they do not. I can supply the…
Conditions: PeptideMeter · 97.6%. I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact. I want to know whether this is…
Details up front: 97.6% · dulaglutide. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
The particulars: liraglutide · 99.1%. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor…
Numbers first: racemisation · orforglipron · minus 20 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…
The specifics, since they change the answer: 99.1% · a wide-pore C18 column · mazdutide. I have the document in front of me and I can read the numbers. What I cannot…
For reference: 97.9% · ecnoglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator because…