Same material, different gradients, different answers
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
Analytics
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Independent analysis puts a SWB dulaglutide lot at 98.6%, against 96.9% on the certificate
The result is unremarkable. What the report omits is not.
Independent analysis puts a WWB semaglutide lot at 95.3%, against 94.2% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Why the independent testing market grew a chemistry arm and not a microbiology one
The absence of microbiological capability in this market is a commercial fact with a straightforward explanation, and it is worth understanding before blaming anybody for it.
Everything on the page, in the order a chemist would read it
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
What VendorInvestigate is able to certify about a sealed vial, and what it is not
Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms, pyrogens, or the integrity of the seal.
Independent analysis puts a CPC orforglipron lot at 95.3%, against 92.5% on the certificate
The result is unremarkable. What the report omits is not.
Chain of custody, and where it begins
The condition on arrival is recorded by some services and not others, and it is one of the more informative lines in a report.
Medutest result on a Suzhou semaglutide lot lands 4.3 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Medutest result on a Shanghai mazdutide lot lands 1.2 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The batch number is the only thing connecting the page to the vial
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
Independent analysis puts a SSA dulaglutide lot at 96.0%, against 95.0% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Medutest result on a Tianjin tirzepatide lot lands 4.3 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
Independent analysis puts a WWB exenatide lot at 97.8%, against 95.3% on the certificate
The result is unremarkable. What the report omits is not.
We split six vials four ways and posted them
Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in full.
Janoshik result on a Chengdu cagrilintide lot lands 1.8 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Independent analysis puts a GL Biochem exenatide lot at 96.5%, against 93.6% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
VendorInvestigate result on a Shenzhen dulaglutide lot lands 2.0 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
Independent analysis puts a SWB tirzepatide lot at 95.6%, against 93.1% on the certificate
The result is unremarkable. What the report omits is not.
Where the solvent front ends is a decision, not a fact
The denominator excludes solvent-front features and injection artefacts by convention. Conventions differ on where the front ends, and a fragment eluting early exists in one…