reading chromatogram threads from 2024 and half of it aged badly
reading chromatogram threads from 2024 and half of it aged badly — a position I have arrived at slowly and would like tested. Retention time shifted 0.4 minutes and I assumed the worst. It was the column temperature. Ran a blank after a high-concentration injection and found the carryover I had been calling an…
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.
Sent the same vial to Medutest and Janoshik. 98.7% against a claimed 98.0%. The difference was the gradient, not the material.
Correction: that is a tailing factor, not a plate count. Different diagnostics for different problems.
What wavelength, and what was the gradient?
Small fix — 214nm, not 210. It matters for the comparison you are making with the other run.
Same view — reporting the gradient is what makes a result checkable rather than merely stated.
system suitability before you believe any number on the run
a shoulder is not an impurity until you can resolve it
ghost peak, check the plumbing first, it is always the plumbing
you cannot report to two decimals off that baseline
Do you have the mass, or only the UV trace?