Sublimation apparatus

Simple sublimation apparatus. Water usually cold, is circulated in cold finger to allow the desired compound to be deposited.
1 Cooling water in 2 Cooling water out 3 Vacuum/gas line 4 Sublimation chamber 5 Sublimed compound 6 Crude material 7 External heating

Sublimation apparatus is a piece of laboratory glassware used in the technique of sublimation usually used by chemists to purify compounds. Typically a solid is placed in a vessel which is then heated under vacuum. Under this reduced pressure the solid volatilizes and condenses as a purified compound on a cooled surface, leaving the non-volatile residue impurities behind. This cooled surface often take the form of a cold finger. Once heating ceases and the vacuum is released, the sublimed compound can be collected from the cooled surface.

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  Camphor being purified on a sublimation apparatus. Note the white purified camphor on the cold finger, and the dark-brown crude product.

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  Dark green crystals of nickelocene, freshly sublimed on the cold finger of the sublimation apparatus.