[Lab] WXT cagri — PeptideMeter came back 97.8% against a claimed 97.0%
Short version of the title, which is already short: WXT cagri — PeptideMeter came back 97.8% against a claimed 97.0%. Longer version underneath. Since the title puts numbers in the shop window: 97.8% and 97.0%. Mass spectrometry answers identity. UV purity answers relative quantity under the run conditions. A…
reproducibility beats resolution if you only get one of them
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.
a shoulder is not an impurity until you can resolve it
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.
Is that baseline drawn by the software or by hand?
two labs, two gradients, two honest answers
report the method or do not report the number
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.