[Below Spec] 94.1% with a 1.8% single impurity. is that the des-amido
94.1% with a 1.8% single impurity. is that the des-amido. That is the headline. The document, the batch and the service are below so you can argue with the method rather than with me.
Pulling the figures out of the title: 94.1% and 1.8%. All of it is written down as it happened rather than reconstructed.
BCH BPC, batch matched the paperwork, PeptideMeter came back 98.6% against a claimed 98.0%. Paid for it myself, posting it because the log is only worth anything if people do.
Tested three lots over a year rather than three vials from one lot. Cost the same and told me something completely different.
If somebody has the same thing measured a different way, post it next to mine and we will see whether they agree.
best — the order this archive was captured in
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.
Small fix — same supplier, different lot. The two rows in the log are not the same batch.
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.
Agreed — the template exists because a result without the batch and the claim is unanchored.
Fourth lot from the same supplier in the log now and the band has been tight the whole way. That consistency is the actual finding.
Fourth lot from the same supplier in the log now and the band has been tight the whole way.
Disagreeing with this line: that gap is ordinary variance, not a contradiction between the lab and the certificate.
inter-lab variance runs a point or two, plan your outrage accordingly
inter-lab variance runs a point or two, plan your outrage accordingly
Adding the boring but useful bit: say whether you paid for it. It is the basis of the whole log.
Push back: three tests on one lot is one lot. It tells you about that lot and almost nothing about the next one.
area percent unless the report says otherwise
area percent unless the report says otherwise
clara_weiss is right that the band matters more than the peak. Consistency across lots is the finding.
I would not post that as a finding. It is a single result and the template asks you to say so.
I would not post that as a finding.
Agreed — and two services on one batch is the strongest thing any of us can produce individually.
That service reports area percent by default. Worth stating, since the thread has been comparing it to a mass figure.
Which service, and did you pay for it yourself?
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.
A series across separate lots estimates a process. Repeat tests on one lot estimate the measurement. Both are useful and they answer different questions.
Left up and added to the vendor source page log. Thanks for paying for it and posting it.
- 1Fourth lot from the same supplier in the log now and the band has been tight…7 comments in this branch · started by u/ewan_marchand