Capillary GC column installation
Brief procedure for column installation
- Cool all heated zones of GC
- Check gas purifiers and if they are spent, replace them.
- Clean injector and detector
- Replace injector/detector liners with new ones.
- Replace critical injector and detector seals.
- Replace septum in the injector.
- Set make-up and detector gas flow rates.
- Carefully inspect the column for damage or breakage.
- Install a nut and ferrule on each end of the column.
- Cut 10 centimeters from each end of the column. Use a sapphire scribe or ceramic scoring wafer to cut fused silica capillary columns. Use the serrated edge of a ceramic scoring wafer or the edge of a sharp file to cut metal capillary columns. See our catalogue for capillary cuting tools.
- Mount the capillary column in the oven using a bracket that protects the column from becoming scratched or abraded.
- Insert column the appropriate distance into the inlet as indicated in the instrument manual.
- Install the column so that the capillary does not touch the oven walls.
- Set the approximate column flow rate by adjusting the head pressure to the value listed on the test chromatogram included with the column.
- Set split vent, septa purge, and any other applicable inlet gases according to the instrument specifications.
- Confirm the flow by immersing the column outlet in a vial of solvent (acetone or isopropyl alcohol).
- Insert column the appropriate distance into the detector as indicated in the instrument manual.
- Check for inlet and outlet leaks using a thermal conductivity leak detector. Do not use soaps or liquid-based leak detectors or the column may be damaged.
- Set injector and detector temperatures. Turn the detector on when the temperatures have equilibrated. Caution - do not exceed the phase's maximum operating temperature!
- To set the proper dead time (linear velocity), inject methane or a non-retained substance compatible with the detector being used.
- Verify system integrity by checking the dead volume peak. It should not tail.
- Condition the column at its maximum operating temperature to stabilize the baseline. (See the test chromatogram included with the column for the maximum temperature.)
- Set oven to appropriate temperature and inject methane or an appropriate unretained substance, again to set the proper linear velocity.
- Inject a duplicate of the original test mixture or your specific test mixture to confirm proper installation, system, and column performance.
- Calibrate the instrument and inject samples.
Note: If the column is new, you have to run conditioning procedure prior setting the proper dead time.
