New LC column pressure is too high

[prk018]

I've been using a PEEK column (C18, 150mm, ID 4.6mm) on our lab's LC, and I tried switching the old column to a new one - it was exactly the same product with the same specifications. But my backpressure suddenly shot up with the new column - with my old column, with 50ul/min of water flow, I've been maintaining ~100bar. When I switched to the new one, now it's almost at 500bar and I don't understand how just switching the column to a system that has already been working well can dramatically increase the backpressure. Can anyone give me some suggestions?

[hplcuserx]

Hello, how are you, it could be several things, it has happened to me several times.
As a guide I found this page that served me, I had low pressure actually "Faulty check valve".

It served me, I recommend it!

Meaby
+Problem in pump, injector, in-line filter, or tubing.
+Obstructed guard column or analytical column.

https://whatishplc.com/hplc-troubleshooting/

[uzman]

What is the particle size of your column , is it sub 2 micron ?
With a flow rate of 50ul/min water flow and 100 bar pressure , it seems like you are using sub 2 micron.

If you are using a high concentration buffer as mobile phase , and connected the new column directly , a buffer precipitation might occurred and a very high pressure observed.

This is because of new columns come with a high concentration of organic solvent inside.

Before connecting the new column directly to a buffered mobile phase , a water rich wash step may be necessary.

[Gerhard Kratz]

You are using a peek column? Maybe the connection is the problem. Do you use a finger tide fitting, do you have stainless steel or peek capillaries? Just cut a little bit of your capillary and connect the capillary fresh with your column. Nothing should be wrong with the column. Don't do body building when you connect a column!

Good luck and stay healthy!

[Ice9]

Column probably stored in ACN, are you sure the pressure difference is just not from pushing the storage ACN off the column, then it will go down to typical levels? I would flush gently with 20 to 50 column volumes and see if the pressure decreases to typical levels as a first step. Solvent fronts can create a lot of back pressure. Especially on small 2.5µ and smaller particles.