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.
PeptideMeter
Page 8 of 8 of this archive, newest first.
What column temperature does to selectivity
Column chemistry, particle size and pore diameter determine what the separation is capable of before the gradient is even programmed.
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.
Set the threshold at a tenth of a per cent and the small impurities vanish
We work through a single chromatogram twice, under two integration conventions, and show where the difference comes from.
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.
Mass spectrometry answers a different question, properly
Where two methods disagree, the conservative convention is to report the lower figure. It is not universal, and whether a laboratory follows it belongs on the report.
How a claim degrades between the bench and the listing
The Journal does not treat a badge as evidence and states so wherever it reports one.
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
What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.