how much of what we believe about HPLC actually comes from gradient threads
how much of what we believe about HPLC actually comes from gradient threads, and I want the answer with the reasoning attached rather than just the conclusion. Gave the same trace to two people I trust and got two integrations about a point apart. That was the most educational afternoon I have had here. Carryover…
Agreed, and it is why FGP printing the column and gradient on the certificate is genuinely useful rather than decorative.
Agreed, and it is why FGP printing the column and gradient on the certificate is genuinely useful rather than decorative.
Disagreeing with this bit: that spread is ordinary inter-lab variance, not a disagreement about the material.
A shoulder that does not baseline-resolve cannot be quantified honestly. You can report it as an unresolved shoulder, which is useful information, or you can develop the method until it resolves.
This. A shoulder that does not baseline-resolve is a question, not a quantity.
a shoulder is not an impurity until you can resolve it
Careful — you are treating retention time as identity. Two things can co-elute and the trace will not tell you.
ghost peak, check the plumbing first, it is always the plumbing
Method questions stay here; supplier claims go to c/vendorvetting with a document attached.
That is area percent, not mass percent. The trace cannot give you the second one.
Retention time shifted 0.4 minutes and I assumed the worst. It was the column temperature.