You can use the MicroSolv sparging stones that have an internal thread of 5-40 with 1/8″ OD (ID can be 1/16th or 1/8th) low pressure polymeric tubing PTFE, PFA, FEP, Tefzel. No fitting will be needed.
The internal thread of the stem acts with small barbs on it. To use the tubing, Insert the tubing into the hole on top of the stone, while pushing down on the tubing turn it as it is threaded by the barbs. Lightly tug on the tubing and pull to create a secure fit. The barbs will grab onto the tubing so it will not slip off.
It may be important to use the internal threaded sparging stones instead of those with fittings to avoid the mixture of many different components in the solvent. This type of connection of the tubing and the stone should not come off in situ as can happen with the tubing/stem configuration.
Click HERE fore sparging stone ordering information and pictures.