I'm fairly new to LC, and I'm trying to figure out what the system pressure for our Agilent 1200 HPLC system is. I'm running phosphate buffers through the system to do SEC, and when I put a union in place of a column, I get around 25 bars at a flow rate of 0.5 mL/min. If I use a column, I get around 28 bars at the same flow rate. The column has a max pressure limit of 200 bars according to the manufacturer's spec.
I understand that I shouldn't operate at the pressure limit of the column, but for my knowledge, given the above scenario, am I right to assume that as long as the total pressure doesn't exceed 25 + 200 (system pressure + column upper pressure tolerance), the column is operating within its pressure limit?
Thanks a lot in advance,