Chromatography Forum

We have a pretty typical LC calibration procedure for all of our RP systems - water/0.3% Acetone for gradient formation and pump mixing tests, caffeine in water for wavelength accuracy, uracil, propyl- and methyl-parabens eluted on a C18 with ACN/water MP...

We have recently dedicated a system for NP only use (different seals) and we'd rather not have to convert it back to RP just for calibration.

So, does anyone have an alternative column and "go to" solvent for doing these same tests?

My initial thought is to substitute propanol for the water. This should allow the same (columnless) procedures to be used for the pump step/gradient formation tests as well as the detector wavelength accuracy.

If nobody sees a problem with that, what do you use for the precision and linearity? Parabens on a silica column with hexane/propanol or something?

Bump for Monday users...

I had hoped someone else would have replied.

Those all sound reasonable to me. The only other thing I could suggest would be to check with the column manufacturer and see what they use as a QC test mix. That should be a reasonable choice for the precision and linearity tests.

An excellent idea even if it's an example of thinking "in the box"!