the purity question that gets asked weekly, answered properly
the purity question that gets asked weekly, answered properly. Change my mind, genuinely — I have no stake in being right about this.
How to build a series that means something, if you are going to spend money on testing anyway.
Three tests on one lot tells you about your measurement. Three tests on three lots, spread over a year, tells you about a process. The second is the one worth paying for and it costs the same.
Buy small, keep the batch numbers, send one vial per lot, and post each one with the claim next to it. After four or five you have something no individual review can give you: a band, a direction and a date range. That is what the source pages are made of.
Kept every report as a PDF with the batch in the filename. Two years in, it is the most useful folder I own.
What a result posted here is actually worth, and how to make yours worth more.
A single figure with no batch identifier is about a vial nobody can locate. Add the batch and it becomes about a lot. Add the claimed figure from the certificate and it becomes a comparison. Add the service and the date and it becomes reproducible. Say that you paid for it yourself and it becomes independent.
Five extra fields, thirty seconds of typing, and the difference between a comment and a row in the log that will still be useful in three years.
Tell me where this is wrong. That is the useful part of posting it.
best — the order this archive was captured in
Area percent and net peptide content are different measurements and most reports give one. Quote which, or the comparison downstream is meaningless.
QYB came back 97.5% on a claimed 97.0%, which is agreement not a discrepancy
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.
Not convinced by the comparison. Different services, different gradients, and you are treating one as ground truth.