by
lmh » Mon May 10, 2021 10:06 am
Yes, either will do the job. There is a theoretical possibility that the one with the larger pore size will delay some really enormous components of the mix that are not currently entering the particles of your column, but this is probably more a theoretical thing than a genuine practical concern. The other guard column, with smaller particles, will add a bit to your back-pressure, so if you have a method that's already pushing your instrument to the utter limit, and you're at that stage where you're anxiously watching the pressure climb, and shaving 50uL/min off the flow-rate because the method is teetering just below your upper pressure limit, you might prefer the large-particle guard column.
But both will offer considerable protection to your column, and neither should be disastrous for your chromatography.