In an ongoing project to adapt microscale techniques to our Basic Organic Chemistry Course we needed a simple, inexpensive and highly efficient vacuum distillation apparatus. Several reactions give liquid products (usually in the 0.2-0.5 mL range) suitable for purification by distillation. Since common microscale equipments were rather inefficient and retained a large fraction (0.07-0.14 mL) of the material after completed distillation we designed a new apparatus. Several test runs with diethylmalonate in our equipment gave a good yield of distilled material and only a small amount remained (approx. 0.025 mL). The apparatus consists of a tube with an NS 10 joint, bent twice and fused to a water cooled condenser. The tube is then connected to a vacuum pump or water aspirator. The distillate is collected in a 1.75 mL glass vial that is tightened with an O-ring or a rubber gasket simply made from a rubber sheet (1-3 mm thick) with a corc-borer. This apparatus has been tried in our student laboratories with very good results. The distillation is fast and efficient and the equipment is very easy to handle.

 

Microdestillation device