Two-piece grease-free sublimer with a flat bottom to enable heating on a hot plate stirrer. Condenser has a large top opening for use with dry ice / acetone or liquid nitrogen. Connection between the flask and condenser is made with a flat o-ring joint permitting parts to be gently separated for maximum product recovery. The capacity listed is that below the bottom of the cold finger. Vacuum control is provided by a 0-8mm grease-free Chem-Cap®; valve. Complete apparatus consists of the condenser, flask, Viton o-ring and horseshoe clamp.