A Schlenk-frit is a laboratory filtration device operating under

inert gas An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...

conditions ( schlenk conditions). It separates air- and water-sensitive

suspension Suspension or suspended may refer to: Science and engineering * Suspension (topology), in mathematics * Suspension (dynamical systems), in mathematics * Suspension of a ring, in mathematics * Suspension (chemistry), small solid particles suspende ...

s into liquid and solid parts. A Schlenk-frit is made of a glass tube with a

ground glass joint Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may ...

at both ends, a fused filter (a porous glass disk) and

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

s at both sides.

Use

Before usage, the Schlenk-frit has to be heated, to remove water traces. The Schlenk-frit is put onto the product flask using an inert gas counterflow and closed at the top end with a second flask. The whole is turned 180° to start filtration. The liquid parts of the reaction mix go through the filter while the solid parts remain. Schlenk frit use

To speed up the filtration pressure can be lowered at the bottom part of the filter. Care has to be taken that the solvent does not evaporate.

References

Laboratory equipment {{chem-stub