This document describes how to replace a column and/or a column guard in an HPLC.
It is the responsibility of the client to ensure that the pump is not running while changing the column and/or
Materials and Equipment
2 – 1/4 x 5/16 open end wrench
New Restek Raptor ARC-18 Guard
New Column - Agilent Poroshell 120 EC-C18 Column
Proper PPE including gloves and goggles are required at all times when working with HPLC systems.
Changing a Guard
1. Ensure the pump is not running using Chemstation or verify that the HPLC is asleep.
2. Remove the top and bottom covers of the HPLC by pushing the grey buttons at the side of the
3. Release the pressure by turning the black pressure valve in the top left corner of the machine
counterclockwise 2 rotations.
4. Confirm this by checking the pressure in Chemstation. It should read less than 3 bar.
5. Loosen the guard holder using the two wrenches by using one wrench on the Holder Body and
one wrench on the Holder Cap.
6. Finish unscrewing the guard holder from the column and remove the guard column cartridge
from the holder, taking note of which direction the guard was facing. The guard can only fit in
7. Replace the old guard with the new guard.
8. Hand-tighten the guard holder back to the column.
9. With the wrenches, tighten a maximum of 1/4 to 1/2 turn past hand tight.
10. Place the column/guard back into the oven and close the bottom cover.
11. Once complete, let the machine sit for 5 minutes as the new guard column cartridge
equilibrates to the appropriate machine temperature.
12. Return pressure to the column by tightening the pressure valve.
13. Turn the pump back on to allow flow to go through the column/guard.
14. Let the machine equilibrate for 10-15 minutes while checking for a leak in the column
apparatus, then run a flush startup.
15. Once complete, you will need to check the calibration of the HPLC.
Changing a Column
1.Ensure that the pump is not running or that the machine is in sleep mode.
2. Open the top of the HPLC by pushing the grey buttons at the side of the machine.
3. Release pressure from the column by turning the black pressure release valve 2 times
counterclockwise or until loose.
4. Verify pressure is low by opening up Chemstation (Online) and looking at the pressure which
should be below 3 bar.
5. Open the bottom of the HPLC by pushing the grey buttons at the side of the machine.
6. Use the 5/16 side of the wrenches and place on the ferrule nut on the left side of the column
and the middle of the column.
7. Loosen slightly with wrenches.
8. Remove wrenches and loosen the nut by hand.
9. Remove the old column from the nut on the left side while being careful not to bend the line.
10. Place the wrenches on the column and onto the holder body (also shown in Figure 1).
11. Loosen with the wrenches.
12. Remove the old column from the holder and screw the plastic ends from the new column into
the old column.
13. Take the new column and point the Flow arrows away from the column guard (should be to the
left as shown in figure 2).
14. Take the guard holder body with the plastic PEEK end going into the column and press firmly
into the column and screw in the column with your hands while firmly applying inward
Important: If enough pressure is not applied while screwing either end into the column the
connection will leak, and it will have to be redone.
15. Use the wrenches on the column and on the guard holder body to tighten the connection.
16. Repeat this connection process with the ferrule nut on the left side of the column.
17. If it is not firmly pressed inward while screwing into the column, the connection will leak.
18. Tighten using the wrenches on the column body and the ferrule nut.
19. Place the column into the oven and replace the cover.
20. Allow the oven to heat up the column for 5 minutes before returning pressure to the system by
screwing the black pressure valve on the top left of the machine until it is snug.
21. Let the machine equilibrate for 15 minutes while checking for leaks in the column apparatus,
then run a flush startup.
22. Replace the top cover of the machine and have customer support observe the Chemstation
results to confirm a good connection with the new column.
23. Once complete, you will need to calibrate the HPLC.