Deactivation of Alumina
Deactivation of alumina allows the chromatographer the flexibility and freedom to deactivate alumina to the precise activity level required for their specific application. Alumina may be deactivated by the addition of polar media, preferably water, but also alcohols such as glycol or glycerol.
Sorbent Technologies’ standardized aluminas are based on a deactivation scale (see chart). Alumina Super I is standardized to such a high degree that all three surface types of aluminas, (acid, basic, neutral) show an identical initial activity, and when deactivated with equal amounts of deactivator (e.g., water), they reach the same lower activity status. The percent of water addition is based upon weight/weight relationships. Activity level is according to Brockmann/Schodder.
Deactivation Procedure:
- Weigh a known quantity of alumina and place it into a tightly sealed vessel.
- Add the required amount of water (by weight or volume.)
- Shake the mixture in the closed vessel until all lumps disappear.
- Allow the mixture to cool (preferably overnight.)
- The container should remain tightly closed to retain activity level and can be stored for later use.