Pump Pressure too High 1312A

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

11 posts Page 1 of 1
Hello,

My Agilent Binary pump 1312A keeps going into error mode (Red Light) after reporting high pressure (exceeding 400 bar).

I tried to identify if there was a blockage some where in the flow path. I figured out that the moment I screw on the column to the capillary, the pressure goes up drastically and the system shuts down. This could be due to some blockage in the column, so I replaced it with a brand new column. However this made no difference !

If I remove the column and simply pump through the capaliries, every thing looks fine.

I am pumping with Iso-prop at 5ml per min and max allowed pressure of 400 bar.

I would be obliged if some one could give a pointer towards a the possible reason ?


Also, I noticed that the moment that I close the purge valve with the column screwed onto the flow capillary, the pump starts to me
Just to be sure: you're trying to pump isopropanole at 5 ml/min through an analytical column and keep wondering about the high backpressure???
sga wrote:
Hello,

My Agilent Binary pump 1312A keeps going into error mode (Red Light) after reporting high pressure (exceeding 400 bar). If I remove the column and simply pump through the capaliries, every thing looks fine.
I am pumping with Iso-prop at 5ml per min and max allowed pressure of 400 bar.
I would be obliged if some one could give a pointer towards a the possible reason ?


I hope you meant 5 microliter/min instead of 5 mL/min for a capillary column. What are your capillaries stored in?
Isopropanol is a relatively viscous liquid. Probably when pure isopropanol is coming in contact with your column storage solution, there is a sudden rise in viscosity. When isopropanol is mixed with water, certain compositions are more viscous than pure isopropanol! This is a common reason to see sudden pressure jumps. Methanol water eluent is another classic case.
If possible, slowly increase the isopropanol fraction with another miscible low viscosity solvent (or column storage solvent like ACN) and begin with a much lower flow rate.
No its not a capillary column.....its a normal Zorbax HPLC column :
250 mm X 4.6 mm column.

By capillary I meant the steel tubing which connects the column heater to the HPLC column.

Yes.... I actually meant 5 ml/ min. Many HPLC methods demand upto 3 ml/ min.

But, hey may be that is the reason, I will try with 1-2 ml per min with diluted medium and report if it helped.
sga wrote:
Many HPLC methods demand upto 3 ml/ min.


But definitely not with isopropanole on a column of that dimensions! As already mentioned, isopropanole is very viscous, even 2mL/min could be too high. I'd rather start with 0.5 mL/min and, depending on the backpressure, increase the flow.
BTW, if this is a new plain vanilla C18 column, why would you want to flush it with isopropanole?

No offense, please, but your practical experience with HPLC seems a bit limited?
Thanks for your suggestions.
Yes, I am not experienced as you, for sure.

So, I want to actually develop a method that does not use very expensive solvents, and thats why I am trying to use Iso-Prop.

Do you know based on your extensive experience, if it is possible to use a mixture of water and iso-propanol for chromatography with a simple column ?

What kind of flow rates do you think are optimal ?

Regards
Also do you think it is possible to use just water as a solvent ?

I tried running water for HPLC, at 1ml/min. Even that didnt work ?

Help !
Try running water at 0.5 ml / min , there still may be IPA in the column and tubings so you can replace it .

After running water at 0.5 ml / min , if the pressure is high ( lets say over 200 bar ( 3000 psi )) , disconnect the capillary at the outlet of the column ( detector side connection ) and check if the pressure drops.

If this is the case , you may have a blockage at the detector cell , inlet and outlet capillaries of the cell , drain tubing etc.
Hi,

I am running the flow line from the column directly into waste at the moment, so there is no connection to the detector flow cell at all. Any ideas ?

Regards
What is the particle size of your column. (5um, 3um, <2um) The smaller the packing size the higher the back pressure will be. If you have <2um then even with pure water you are not going to be able to go above 1ml/min without having pressures of 200-400bar.

I would begin with 0.2ml/min using pure water, if that flows without over pressuring then slowly increase the flow until you are in the 300bar range. For your co-solvent I would go with Methanol since the price should not be much different from isopropanol and it will give lower pressures.

What will you be trying to separate? This will give us more information to help you select the operating parameters you will need.


Also you can take the column temperature up to 40C an it will help lower the back pressure by lowering the viscosity.
The past is there to guide us into the future, not to dwell in.
The summary of your problem :

When you pump without column - no problem.
When you pump with column without detector connection - problem.
Your column is 250x4.6mm , so the particle size can not be smaller than 3 mikrons.

The problem seems related to column.
11 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 1117 on Mon Jan 31, 2022 2:50 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry