Reproducibility, measured rather than assumed
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.
Janoshik Analytical
Page 3 of 7 of this archive, newest first.
The named comparison we promised two years ago
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
Blind duplicates: what happens when a laboratory does not know it is being watched
Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from between-laboratory reproducibility.
Size exclusion sees the thing reversed-phase dissolved
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.
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.
Why purity is the cheapest number to flatter
Peptide content, identity, aggregate burden, moisture and endotoxin are all more informative for some purposes. All of them cost more.
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.
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.
Three services, one lot, and a spread of two and a half points
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.
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.
Six words a verification badge would need to mean anything
What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.
The badge economy, and what it is actually certifying
Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.
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…
What a split-sample exercise can establish, and what it cannot
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.
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.
What column temperature does to selectivity
A shallow gradient resolves impurities that a steep one runs into the parent peak. Both methods are legitimate; only one of them can see the small stuff.
The badge is about a sample. The listing is about a product.
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.
What a laboratory knows about the material it receives
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.
Six words a verification badge would need to mean anything
What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.
What a diode array adds, and why the certificate never shows it
A diode-array detector records the whole spectrum at every time point and can confirm that a peak is spectrally homogeneous. Almost nobody prints that information.