u/mariam_cabrera

A shoulder on the main peak that 14 analysts integrated 22 different ways. Same trace, 97.4 spread.

A shoulder on the main peak that 13 analysts integrated 19 different ways. Same trace, 98.6 spread.

axis labels included, always

Inter-lab variance on this kind of assay is routinely 1–2 points. Different column, different gradient, different integration.

Which VendorInvestigate service and what method did they use?

area% and mass% are not the same and this whole post conflates them

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

Detection wavelength? method development and that changes at different wavelengths.

Ireland here. Waited 23 months on a list, gave up, went private, and the total cost was roughly what I expected.

the 98.1% result confirmed the vendor claim, that is the signal Yes, exactly this, and it is the bit that took me 9 weeks to accept.

Disagree on that part. 99.0% and 98.9% on the same vial is normal.

multiple batches from BCH show a spread, that is the data

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

regulatory status changed in 20 countries, check yours

Not to be pedantic but batch and purity are being used interchangeably and they are not interchangeable in real life.

rapid loss plus no protein equals muscle loss

reship and retest is the honest way to handle a low result

The Janoshik result being close to my own HPLC is the signal, not the absolute number. Both are right.

lane reports need origin, destination, carrier, actual transit days

Yeah, protein matters on rapid loss.

What was the column and what gradient?