Follow-up: How to disagree with an answer you were given, well

How to disagree with an answer you were given, well I have a specific reason for asking rather than idle curiosity, and the context is below.

Question in the title. Context below, and I have tried to include the things people here always have to ask for.

What I have already read: the relevant maintained document, the two topics it links to, and the tag page. What I could not find is the specific case I am in, which may simply mean it is uncommon.

I am happy to be told this is answered elsewhere if someone can point at where.

the opening post answers the question as asked. The question underneath it is different.

Asking a follow-up: new topic or reply in the old one? If the answer depends on the previous post, reply. If it is a question that makes sense without the previous post, new topic. The second gets faster answers.

Chromatogram questions: describe the method first. Column type, gradient, wavelength, detection method. Everything else follows from method. A chromatogram without method is a number without context.