Guard column and HPLC column compatibility

[nomfreak]

I have been using a Kinetex PFP column, 100 mm x 2.1 mm, 2.6 uM, 100A (it has an effective filter pore size of 0.2 uM) and an Opti-Solv EXP pre-column filter (with titanium Hybrid ferrule) that also has a 0.2 uM pore size. Is there any reason that these two should not be compatible? I had an issue with my new column becoming clogged, but the guard column was not clogged. I can't imagine how the sample could pass through the guard column and not the actual column. I am using filtered plasma samples acidified with TFA. I have used these samples with an identical setup in the past with no problems. I am also filtering the plasma and precipitating proteins.

The company that makes the column claimed it was likely because I was not using their guard column, but this one has been fine in the past, and it appears to be compatible based on the specs. I am awaiting to hear from the company that makes the guard column.

Any ideas? Thank you in advance!!!

[Sazabi]

Hi,

I have the exact same column and it clogged a while ago too. But I try to wash it according to the manual and now it worked just fine.

I don't exactly know what caused the problem, but it was new (usually they ship in ACN) and I did not wash column with water before I run my phosphate buffer mobile phase. So it may be the phosphate precipitate due to the high buffer conccentration? (Anyway, is your mobile phase phosphate buffer?)

Since your guard column was used, so the precipitation is occurred in the kinetex column?

I suggest a wash/flush can regenerate your column.