first time use equilibration of columns? (PLRP-S)

[miro2009]

Hello chromatographers,
I would like to ask your opinion about below problem, that I also described to Agilent and waiting for their feedback:
"We re having a problem with a recently purchased PLRP-S 3 um (4.6x150mm) column. We have a previous experience with using this specific column in addition to the same resin in other dimension (5 um, 4.6 x 250mm) and our samples have a certain known profile on such columns. With the recently purchased column we noticed deformed and unsymmetric peaks. generally a very unacceptable profile form our side. We assumed it could be a problem of column equilibration for 1st use as some manufacturers recomend injection of Ribonuclease or Albumin several times. What we did is inject our sample several times and noticed very gradual improvement but still not our expectance. We tried injection of Ribonuclease but didn't add an advantage. Finally, we performed a column "cleaning" as we usually do for this resin by 0.5M NaOH 4 column volumes and rinsed with water. After that we observed a significant improvement in our sample profile but again not reaching our expectance.
We were wondering if you have an explanation for this, and if its a matter of column 1st use equilibration, how do you suggest we perform this to finally reach a constant column performance?"

I would appreciate if anyone had a similar experience or an explanation for this. Thank you
Maria

[tom jupille]

What are you doing differently this time? If you are equilibrating the same way that you have done successfully in the past, then this is probably a bad column. I would ask for a replacement.