[Discussion] the method development advice in here is 2 years out of date
the method development advice in here is 2 years out of date, and I am aware this is a minority view on this board.
2 years. Those are measured, not estimated, and not rounded up in my favour.
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.
That is everything I have. The rest is opinion and I have tried to keep it out.
best — the order this archive was captured in
Retitled: the original claimed a comparison the post does not actually make.
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.
Chased a ghost peak for three weeks. It was the plumbing. It is always the plumbing.
Yes — system suitability first. Without it the number is an assertion about the instrument, not the sample.
two labs, two gradients, two honest answers
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.
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.
Is that baseline drawn by the software or by hand?
[deleted]
214nm sees the peptide bond, 280nm sees the aromatics
That figure cannot be quoted to two decimals off that baseline. The precision is not in the data.
What did system suitability look like on that sequence?