Cannula Transfer - Handling Pyrophoric Material

Handling Pyrophoric Material

While handling pyrophoric material (e.g. tert-butyllithium and trimethylaluminum), traces of the compound at the tip of the needle or cannula may catch fire, and cause a clog. Some workers prefer to contain the tip of the needle or cannula in a short glass tube flushed with an inert gas, and sealed via two septa.

Instead of exposing the needle tip to the air, it is withdrawn into the inerted tube. Where desired, it may be inserted into a flask via two septa (one on the tube, one on the flask). Used this way, needle tip fires are eliminated, reducing the obvious hazards. Also, there is a reduced tendency for the needle tip to clog due to the reaction of traces of the reagent with air to give salts.