This short movie shows the Schlenk apparatus for the work under vacuum or inert gas atmosphere. Aside from the explanation of the equipment and the set-up, many valuable tips and advices are given.
A Schlenk line serves the purpose to avoid water or oxygen in your apparatus. To accomplish that the Schlenk line is connected to a powerful vacuum pump equipped with two cooling traps as well as to a source of inert gas from which water and oxygen have been removed beforehand. The following should be taken into account when working under Schlenk conditions:
Before work you have to purge your apparatus at least three times with inert gas, which means to evacuate for about 15 min. and then to vent with inert gas repeatedly.
The ground glass joints have to be greased properly, which means neither using too small amounts of grease, as the apparatus will be leaky or parts might get stuck, nor too much as grease might accidently get inside the apparatus and conaminate the target compound.
It is advantageous to mark affiliated Schlenk valves and tube ends in the same colour to avoid mix-ups. Moreover, this way it is easier to differentiate between vacuum and inert gas.
If you are working a long time with the line or if you want to evaporate larger amounts of a solvent you should check the cooling traps' dewars' filling level of liquid nitrogen regularly.
For the reaction of very sensitive compounds it is recommended to prepare the assembly of the apparatus with hot components directly from the drying cabinet to evacuate as fast as possible and to avoid any condensing water on the surface of the glassware during the cooling process.
If two constructions are to be connected under inert gas conditions you will have to do it in the counterflow while an overpressure of inert gas flows through both of the joining parts and contact with air can be avoided. Nevertheless, you should work as fast as possible under such circumstances.
