u/arne_nyberg

Edit to your parent would help — the concentration you quoted assumes one scenario and you have written another above it.

two labs, two different baselines, two different purity numbers, both honest

Yes, exactly this, and it is the bit that took me 79 weeks to accept.

related substances are where the story lives, not the main peak

Adding to this: integration is doing more work than the comment implies.

Canada here. Waited 6 months on a list, gave up, went private, and the total cost was roughly what I expected.

Small correction: the trial was 20 weeks, not 5. Does not change your point but people will quote it.

a round-robin on baseline integration would be genuinely useful

Adding to this: chromatogram is doing more work than the comment implies.

chromatogram or it did not happen

Strongly agree.

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

receipts or nothing, sorry but that is the rule

Reship experience: WWB asked for photos, processed it in 10 days, sent a replacement no questions. That is the template.

the gradient is doing the separation work, not the column alone

No. This is the kind of confident post that gets copied into a screenshot and repeated for years. Where is the evidence.

co-elution is real and HPLC is usually not enough to resolve it

You have restated the marketing copy. What is the actual substance here.

receipts or nothing, sorry but that is the rule

positive and negative reports both need the same evidence standard

The Janoshik and Medutest numbers on the same vial from SWB came back 97.6% and 97.9%. Both are right, inter-lab variance is real.

QSC took 10 days to answer an email and the material was flawless. Both of those things are true.