Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot traceability, and the single most common trap - reading area-per-cent purity as if it were content.
This is my second independent submission on material from the same supplier. I can find plenty of assertions about this and almost no reasoning, which is usually a…
What I have: a GLP-1 receptor agonist · sixteen weeks · 30 °C. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone…
What I have: 99.4% · Janoshik · 97.1%. Before I write this off, I want to check whether it is a known failure mode. I have the lot number, the certificate and the…
Details up front: KP · a quantified content assay. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary;…
The particulars: liraglutide · PeptideMeter. I have the document in front of me and I can read the numbers. What I cannot do is interpret them. I am reasonably…
The lot number on the vial matches the certificate, which at least rules out the easy problem. The figures are clear enough; the question is what they mean and what…
What I am working with: Medutest · Shanghai Sigma-Audley. I have read the primary source rather than the summary, which has left me with more questions. I understand…
For reference: date of analysis · HJ. I would like to define my thresholds before I have a result, for obvious reasons. I want a plan with explicit stopping rules,…
Numbers first: 98.2% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…
Stated plainly: 97.6% · a C18 column · ecnoglutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
The method section is present, which is unusual enough that I want to make use of it. I would like to set this up properly once, rather than adjust it repeatedly. My…
Concretely: PeptideMeter · liraglutide. I have done this once and I suspect I got away with it rather than got it right. For context: I keep records of every batch,…
What I am working with: 95.2% · Medutest · 99.4%. This is not behaving the way I expected and I want to understand the discrepancy before I act on it. I have…
What I am working with: retatrutide · two weeks · minus 20 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have…
Stated plainly: lot-specific certificate · SGN. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided…
The particulars: MKM · Chinese Peptide Company. I am trying to choose between two options that are usually discussed as though only one exists. I am not optimising…
I have the report as a PDF with the chromatogram on page two, so I can quote specifics. I am at the decision point and I would rather think it through than improvise.…
What I have: KP · WuXi TIDES. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is reproducibility,…
Details up front: WWB · Shanghai ERP Biotechnology. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…
What I have: JEEP · Qingdao Sigma Chemical. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a defensible…
This is my second independent submission on material from the same supplier. I have the document in front of me and I can read the numbers. What I cannot do is…
For reference: GL Biochem · a residual-solvent screen. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that…
I am comparing three suppliers on documentation rather than on price. I have done this once and I suspect I got away with it rather than got it right. For context: I…
Concretely: chromatogram · GGPeps. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like the plan…
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
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