The principle of subboiling

Sub-boiling distillation is recognized as the best method to obtain high purity reagents and the lowest blank values for ultra-trace analysis. Sub-boiling distillation is based upon vaporizing a liquid by infrared heating of its surface to avoid boiling. This technique prevents the formation of aerosol or droplets.
In conventional distillation, violent boiling action generates aerosolized particles, resulting in contamination of the original liquid with the distillate.
Surface evaporation during sub-boiling distillation prevents this, thus yielding a higher purity distillate.

How DuoPUR and SubPUR work

The DuoPUR consists of two high-purity quartz distillation units.
Each unit contains two heating elements (which supply a maximum power of 1250 W), a water cooled condenser, reagent addition, and high purity collection bottles.  Click on video link to see the DuoPUR in action.

The distillation process is microprocessor controlled, allowing the user to set the distillation time and power level.
Infrared heating gently vaporizes the surface liquid, accelerating evaporation, and preventing aerosolized particles.
Vaporized liquid is collected on an inclined cold finger where it condenses and drips into the high purity PFA collection bottle.

The SubPUR system perform the same process, but is equipped with only one sub-boiling distillation unit.