The unique threaded connector at the top of this apparatus permits adjustment of the distance between the cold trap and the bottom of the apparatus, depending upon the amount of substance in the bottom and the rate of sublimation, without stopping the process. This is important when working with highly sensitive chemicals. Approximate volume of the lower chamber is 100mL and is useful for subliming samples in a range of 1 to 13 grams, depending on the density of the material.
As the chemical is sublimated and crystallized on the surface of the cold trap, with the crystals growing in size with time, they can eventually come into contact with the impure chemical in the base. A simple adjustment of the cold trap position prevents this from happening, without interruption to the sublimation process.
Cold trap with expansion bellows, silvered and evacuated
Heavy wall glass with threaded nylon compression bushing and o-ring seal
Upper to lower chamber flange with o-ring seal and SS/composite chain clamp
10mm high vacuum valve with 8mm hose connection
Maximum distance from bottom of cold-finger to bottom of vessel is 45mm
Aldrich is a registered trademark of Sigma-Aldrich Co. LLC