Reproducibility, measured rather than assumed
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.
Peptide content
Page 9 of 10 of this archive, newest first.
The impurity hiding underneath the parent peak
The most useful single addition to any purity determination is a second separation under a different pH or on a different stationary phase, and the second-most useful is a…
Why two wavelengths on one run would settle several arguments
Non-chromophoric components — counter-ions, salts, some excipients — contribute mass to the vial and nothing at all to the chromatogram.
Twelve things a real certificate has, and what their absence means
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
Why a result on one vial says less than the trade needs it to
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.
When a template becomes a misrepresentation
A blank certificate with the numbers left editable is an ordinary internal document. Its circulation as a finished record is the problem.
How a claim degrades between the bench and the listing
Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.
The submitted sample: the weakest link in the whole system
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.
The named comparison we promised two years ago
The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and published each method alongside each result.
Who signed this, and what did they undertake by signing it
Two signatures — one who performed the work, one who approved its release — are the ordinary regulated convention and are almost unknown here.
What a laboratory knows about the material it receives
The condition on arrival is recorded by some services and not others, and it is one of the more informative lines in a report.
The impurity hiding underneath the parent peak
An orthogonal method separates on a different physical principle, so that species co-eluting in the first are likely to resolve in the second. Two runs of the same method at…
The badge is about a sample. The listing is about a product.
The Journal does not treat a badge as evidence and states so wherever it reports one.
A named analyst is the cheapest quality signal in this trade
What the Journal asks when a document arrives unsigned, and what the answers have been.
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.
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.
The submitted sample: the weakest link in the whole system
Every third-party report in this market describes a sample somebody chose to send. That choice is outside the laboratory’s control and outside its records.
What orthogonal actually means, and what it does not
The most useful single addition to any purity determination is a second separation under a different pH or on a different stationary phase, and the second-most useful is a…
What the paperwork is for, and who it was designed to protect
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
The submitted sample: the weakest link in the whole system
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.