[Question] is 99.2% actually fine or am I being sold a rounding error
Title says it — is 99.2% actually fine or am I being sold a rounding error — so here is the boring supporting detail that makes it worth anything. The relevant figures are 99.2%, and they come from the same log I have kept the whole time. The system suitability argument, since it comes up whenever somebody posts a…
Yes. Retention time is a hypothesis about identity. Mass is the answer.
What wavelength, and what was the gradient?
That is area percent, not mass percent. The trace cannot give you the second one.
Push back: a longer run is not automatically better resolution. You are trading peak width for time and the ratio is what matters.
System suitability — repeat injections, tailing factor, plate count, RSD on area — is what tells you the instrument was fit for the measurement that day. Without it, the purity figure is unanchored.
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.
Ran a blank after a high-concentration injection and found the carryover I had been calling an impurity.