A separating funnel or separation funnel or separatory funnel is a piece of laboratory glassware used to partition the components of a mixture between two immiscible liquids of different densities. It is also referred to by a shortened version of its name, a "sep funnel"

Typically, one of the liquids will be water, and the other an organic solvent such as ether or chloroform. The funnel, which is in the shape of a cone surmounted by a hemisphere, has a stopper at the top and a tap at the bottom.

To use the funnel, the two liquids (one containing the mixture in solution) would be poured in through the top with the tap closed. The funnel is shaken, inverted and the tap carefully opened to release any excess pressure, then allowed to settle. Then the tap can be opened to allow the more dense liquid to be transferred to another vessel. The user must be careful to close the tap exactly when all of the more dense liquid has evacuated the funnel. This requires a certain amount of skill. The remaining liquid can then be transferred to wherever it is needed.

See also

• Laboratory funnel
• Multiphasic liquid for systems of more than three liquid phases

Laboratory glassware | Wet chemistry

Ampolla de decantación | Ampoule à décanter | Scheitrechter | 分液ロート