does LC-MS actually matter or is it forum lore at this point
does LC-MS actually matter or is it forum lore at this point. I am not trying to be the "source?" guy. I would just like a source.
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.
Retention time shifted 0.4 minutes and I assumed the worst. It was the column temperature.
Bought a second-hand instrument and learned more in six months of fixing it than in three years of reading traces.
Research-use-only material is not approved for human use and nothing here should be read as a recommendation to use it.
best — the order this archive was captured in
Carryover from a previous high-concentration injection looks exactly like a small impurity. The blank injection is four minutes and it removes the ambiguity entirely.
Started reporting my own integrations with the baseline choice stated. Arguments in my threads dropped by about half.
Careful — you are treating retention time as identity. Two things can co-elute and the trace will not tell you.
Left up. The integration disagreement in this thread is the most useful thing on the board this week.
Agreed. Two analysts, one trace, two integration choices, and a spread that has nothing to do with the vial.
Same method at both labs, or two different gradients?
Chased a ghost peak for three weeks. It was the plumbing. It is always the plumbing.
Resolution between two peaks depends on retention, selectivity and efficiency. A shallower gradient buys retention and usually resolution, at the cost of peak width and run time.
Push back: a longer run is not automatically better resolution. You are trading peak width for time and the ratio is what matters.
Area percent is the integrated area of your peak over the total integrated area at one wavelength on one gradient. Change any of those and the number changes without the sample changing.
What did system suitability look like on that sequence?