Submitting a sample: the process end to end

On the subject in the title: Submitting a sample: the process end to end Working notes rather than a conclusion.

I would like to talk about documentation quality as a signal, separately from product quality.

Across the certificates I have collected, the variation in what is disclosed is much larger than the variation in the purity figures. Some name the analytical procedure; some give a number and a signature.

My hypothesis is that disclosure correlates with process control, and I would like to know whether the people who audit paperwork for a living think that is naive.

Picking up post #2: that is the part I would want checked first.

VendorInvestigate: documentation and supplier-practice review. Reviews paperwork rather than vials. Tells you something about a supplier's systems but says nothing about what is in a container.

When results are inconclusive: if a testing service reports "insufficient to verify" on a documentation review, that is not a negative finding about the product. It means the documents did not contain enough to check.

Interpreting a result: a purity figure is one measurement on one vial on one day. Agreement across two services is much stronger. A single high number does not establish a pattern.

How to submit a sample: contact the service directly. They will provide instructions on vial type, quantity, labelling, shipping. Following their instructions exactly ensures results are interpretable.

This follows post #55 rather than contradicting it.

Blind sampling: submitting without the laboratory or seller knowing the source removes the two easiest ways for a result to be shaped: selective submission and selective reporting. The extra effort is worth it.

VendorInvestigate: documentation and supplier-practice review. Reviews paperwork rather than vials. Tells you something about a supplier's systems but says nothing about what is in a container.

Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.

Worth separating two things that post #99 runs together.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.