Vacuum Filtration

Receiving flasks

There are two main setups employed with vacuum filtration. These are outlined below


Buchner flask setup

Photo showing the correct setup for a vacuum filtration using a buchner flask. A buchner flask is secured to the fume hood racking using a boss and clamp and it sat on the floor of the fume hood. A piece of vacuum tubing is connecting the sidearm of the buchner flask to the vacuum line. On top of the flask is a buchner ring and then sinter funnel.

This consists of a Buchner flask, Buchner ring and the funnel is placed through the Buchner ring into the Buchner flask. The Buchner flask is a thick walled vessel, specifically designed for vacuum filtration. However, the collected filtrate will require transferring into another vessel if this is to be used.


Filter adapter setup

Photo showing the correct setup for a vacuum filtration using a filter adapter setup. A round bottom flask is clamped securely to the fume hood racking using a boss and clamp around the ground glass joint. A filter adapter is sat in the ground glass joint, with vaccum tubing attached the sidearm and connected to the vacuum tap. On top of this is a rubber seal and sinter funnel.

These setups are often employed where collection of the filtrate is desired, and thus is only suitable for use with a sinter. The advantage of this method is that there is no need to decant material prior to the next step. Filter adapter setups are most commonly employed where the next step for the filtrate is a rotary evaporation.


In this setup the bottom of the sinter deposits the filtrate directly into a round-bottomed flask.