It is reported that the cause of 85-90% of problems during analysis can be found in the inlet. Therefore, do not forget to regularly replace all consumables. The liner, septum and all seals have a limited lifespan!
Sometimes, however, replacing consumables or cutting the column is not enough. Then it is necessary to clean the supply. General instructions can be found below, but always follow your manufacturer's instructions first and foremost!
Cleaning
Cool the inlet. The temperature should not exceed 40°C.
Turn off the carrier gas flow.
Uninstall any autosampler.
Uninstall the column.
Open the inlet, remove all consumables.
If possible, it is preferable to disconnect the split branch of the pneumatic system from the inlet.
The inlet now consists of just a metal tube, which may or may not be tapered at the end.
There are various tools that can be used for cleaning (eg a grater). Using such a brush and methylene chloride and methanol, move down and clean the intake.
Using a pipette, spray the inlet with solvent (capture the solvent under the inlet in a beaker) and make sure that no dirt particles remain in the inlet.
To remove residues, insert and heat the inlet to approx. 65 °C.
Reinstall the split branch of the pneumatic system, install new consumables.
Turn on the carrier gas flow. Check for leaks.
Allow the supply to flush for at least 10 minutes before increasing the temperature. Remove residual oxygen. A premature increase in temperature may activate and degrade the new consumable.