Here are normal pump pressure ranges for our columns:

PP-ODS for DA and 5HT – 7.5 to 10 MPa

AC-GEL for ACh – 4.5 to 6 MPa

CA-5ODS for NE and E – 8.5 to 11 MPa

GU-GEL for Glutamate – 5 to 7 MPa

SC-5ODS for Monoamines – 6 to 9 MPa

SC-3ODS for Monoamines – 9 to 13 MPa.

AC-GEL for Acetylcholine- 4-6 MPa

CAX for NE, DA, 5-HT- 7 to 9 MPa

NOPAK (ENO-20) for Nitrite and Nitrate-1.2-1.8 MPa

These values are just for reference.  Longer tubing causes higher pressure.

Higher pressure may indicate that it is time to replace the precolumn. However, the higher pressure is just one of the reasons to repack precolumn. Please check the precolumn quality by injecting standard samples without precolumns and directly to the separation column. If the removed precolumn was the factor of bad separation, the separation should be improved when the injection is made without the precolumn.

 Lower pressure normally indicates the pump is having a flow problem.  Please compare the measured flow rate with the set value. If the pressure and flow rate is lower than expected, it is most likely caused by air in the pump.  Please see how to remove air from the pump.