Chromatography Forum

Recently purchased a re-furbished Waters 2695 with RID for SEC/GPC analysis. I am new to the Waters systems (but have run Dionex previously). The technician that did the installation and familiarization basically told me that I could just start running my samples after the system had equilibrated and that there was no need to prime/wash/purge etc. on a daily basis.

Since I am extremely skeptical of his advice, I wanted to know what other users do in terms of their daily start up routines, especially for an older "well used" system like this.

Also, a question about wet priming on this system - are the columns bypassed during a wet prime? I have 2 columns in series that have max flow rates of 1 mL/min.... and I don't want to destroy them. Most things I've read say to wet prime at 5.0 or 7.5 mL/min.

Thank you!
-LC

Yes, as with all reasonably modern systems, columns are bypassed when priming a 2695. Keep lines full and you should be able to get away with lots of daily use w/ minimal fuss. Remember to shut your degasser (assuming you have one) off during your shutdown/cleanout sequence.

RI detectors also need to be flushed (ref loop, then switch to main) and they are notoriously slow to equilibrate to running conditions, so allow lots of time and extra mobile phase for that.