Building on post #5 rather than restating it.
Mobile-phase preparation is a genuine source of between-laboratory variation. Acid concentration and organic modifier both shift retention, and neither is usually specified to the precision that would matter.
Two people can read the same figure differently here and both be reasonable.
Noted, and I have changed what I was going to do on the strength of it.
Coming back to post #18, because the follow-up matters more than the original answer.
I would keep carryover and the decision it usually gets used for separate in this thread. They are related and they are not the same question, and merging them is why the last one went badly.
Post #27 is the version of this I will quote in future. One addition.
Trying to state the carryover position in a way that someone who disagrees would recognise as fair, because I do not think the version in this thread passes that test.
Column chemistry and particle size: smaller particles (1.7 μm) give better resolution and higher efficiency than larger particles (3.5 μm or 5 μm), at the cost of higher back pressure. Newer methods increasingly use smaller particles.
One more caveat and then I will stop qualifying: the sample selected itself.
This follows post #37 rather than contradicting it.
Peaks that do not elute do not appear in the area percentage. Aggregates and strongly retained species can be entirely invisible to a standard method, which is a ceiling on what any purity figure can claim.
A weak preference rather than a position.
Peaks that do not elute do not appear in the area percentage. Aggregates and strongly retained species can be entirely invisible to a standard method, which is a ceiling on what any purity figure can claim.
The confident version of this sentence would be wrong, so here is the hedged one.
If you are new and reading this thread for the answer to carryover: the answer is conditional, the conditions are in the third reply, and the rest of the thread is worth skipping.
What I can speak to on carryover is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
Read the full topic (93 posts)
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