the Janoshik question that gets asked weekly, answered properly
the Janoshik question that gets asked weekly, answered properly. It is the sort of thing everyone half-believes and nobody writes down.
BCH BPC, batch matched the paperwork, Janoshik came back 99.6% against a claimed 99.0%. Paid for it myself, posting it because the log is only worth anything if people do.
Chain of custody is why member-funded testing is worth more than a supplied certificate: the vial tested is the vial that arrived at a member’s door.
Date of analysis anchors the result to a manufacturing period. A two-year-old result is evidence about two years ago and should be read that way.
I will update this if the picture changes rather than quietly leaving it up.
best — the order this archive was captured in
The template is vendor, compound, batch, service, claim, result, and who paid. Every one of those fields exists because a result missing it has been argued about here before.
Inter-lab variance on this assay runs roughly a point either way, driven mostly by gradient and integration. Two results inside that band agree; they do not disagree quietly.
Inter-lab variance on this assay runs roughly a point either way, driven mostly by gradient and integration.
This is why the template has a batch field. Without it the result is about a vial nobody can identify.
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Which service, and did you pay for it yourself?
Do you have the trace, or only the summary?
How many separate lots does your series cover?
Split one vial between VendorInvestigate and Medutest. The two numbers were within half a point of each other and I stopped worrying about which lab to trust.
GL Biochem came back 98.3% on a claimed 98.0%, which is agreement not a discrepancy
On inter-lab disagreement, which generates more heat here than anything else.
Two services running different gradients, integrating differently, at possibly different wavelengths, will not produce identical numbers on the same material. A point either way is ordinary. Half a point is close agreement.
The productive response to a gap that size is to post both results with both methods and let the log accumulate. The unproductive response is to pick the lower number, call it the truth, and open a dispute. Members have done the first for long enough now that the bands in the vendor tables are genuinely informative.
If the report gives a mass spectrum as well as UV purity, say so. Identity and relative quantity are separate claims and the log tracks both.
Right, and a point or two between services is ordinary. It is agreement, and every month somebody posts it as a scandal.
This. The trend across separate lots is the number that tells you about a process rather than a vial.
Push back: three tests on one lot is one lot. It tells you about that lot and almost nothing about the next one.
Disagree that this is a discrepancy. 98.7% against a claimed 98.5% is inside ordinary inter-lab variance in either direction.
I would not post that as a finding. It is a single result and the template asks you to say so.
inter-lab variance runs a point or two, plan your outrage accordingly
- 1The template is vendor, compound, batch, service, claim, result, and who…6 comments in this branch · started by u/piotr_nascimento
- 2On inter-lab disagreement, which generates more heat here than anything…6 comments in this branch · started by u/reship_roulette