u/downvote_magnet

Area percent is the integrated area of your peak over the total integrated area at one wavelength on one gradient.

Disagreeing with this bit: that spread is ordinary inter-lab variance, not a disagreement about the material.

That figure cannot be quoted to two decimals off that baseline. The precision is not in the data.

the clothes change before the number does

Do you have the mass, or only the UV trace?

Bought a second-hand instrument and learned more in six months of fixing it than in three years of reading traces.

How old is the column and roughly how many injections has it seen?

a shoulder is not an impurity until you can resolve it

progress is not linear and nobody’s is

Agreed. Two analysts, one trace, two integration choices, and a spread that has nothing to do with the vial.

Mass spectrometry answers identity. UV purity answers relative quantity under the run conditions. A document with one and not the other is answering half the question, and the half it answers should be stated.

Right. And a blank between injections settles the carryover argument before it starts.