PeptideMeter result on a Wuhan orforglipron lot lands 2.1 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Analytics
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Independent analysis puts a GGPeps tirzepatide lot at 95.4%, against 92.1% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Independent analysis puts a HJ dulaglutide lot at 95.0%, against 93.3% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Two analysts, one chromatogram, two answers
Chromatographic software does not integrate every fluctuation in the baseline. It applies a threshold, and the threshold changes the reported purity by amounts that matter…
Reading a certificate as a document rather than as a score
Nothing on this page is difficult. It is simply unfamiliar, and unfamiliarity is what makes a weak certificate look like a strong one.
A vial can be 99.4 per cent pure and not sterile in the same afternoon
The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what a reader is filling in from imagination.
Independent analysis puts a CPC mazdutide lot at 97.5%, against 94.0% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Medutest result on a Hangzhou liraglutide lot lands 4.1 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
The badge economy, and what it is actually certifying
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.
Retest date, expiry date, and the two conventions being confused
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.
VendorInvestigate result on a Changsha orforglipron lot lands 1.6 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Oxidation, and the peroxide that came in with the surfactant
Deamidation, oxidation, aggregation and hydrolysis account for nearly all of what happens to a peptide over time. Each has a characteristic residue, a characteristic…
VendorInvestigate result on a Nantong dulaglutide lot lands 0.9 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
Independent analysis puts a CPC cagrilintide lot at 98.4%, against 96.3% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Bacteriostatic water, sterile water, and the 0.9 per cent that makes the difference
An in-use period is established by a dedicated study on a specific formulation in a specific container at a specific concentration. Borrowing one from a marketed product is…
Same mass, different molecule: why identity by mass is not identity
An isoaspartate rearrangement changes the molecule and not the mass. A method that confirms identity by molecular weight alone will report it as the parent compound.
Who signed this, and what did they undertake by signing it
Accreditation is granted for a defined scope of methods. A laboratory can be properly accredited and the test on your certificate can sit outside it.
Independent analysis puts a TFC cagrilintide lot at 95.9%, against 95.2% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
VendorInvestigate result on a Xianning liraglutide lot lands 2.5 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Janoshik result on a Hangzhou retatrutide lot lands 0.8 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.