Description General description Safe alternative for distillation of heat-sensitive compounds. The material is in contact with the heated center finger for only a brief period of time, avoiding decomposition by long-term exposure to heat. This system can be used at atmospheric or reduced pressure. Look at these products on the web at sigma-aldrich.com to see a typical distillation set-up. Falling Film Technique 1. Flask A is filled with the solvent desired and heated to reflux. The boiling solvent vapor maintains a constant temperature at the center finger. The temperature is the boiling point of the solvent. 2. The material to be distilled is placed in the addition funnel and allowed to drip slowly onto the heated center finger. The volatilized material will condense on the outer air-cooled wall and collect in Flask B. The high boiling material will remain on the center finger and flow down the spiral into Flask C. 3. Any pressure-equalizing funnel, standard condenser, and flasks can be used. Legal Information Aldrich is a registered trademark of Sigma-Aldrich Co. LLC