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:

  1. Weigh a known quantity of alumina and place it into a tightly sealed vessel.
  2. Add the required amount of water (by weight or volume.)
  3. Shake the mixture in the closed vessel until all lumps disappear.
  4. Allow the mixture to cool (preferably overnight.)
  5. The container should remain tightly closed to retain activity level and can be stored for later use.
Deactivation of Alumina

The term “deactivation of alumina” could refer to a number of different processes or treatments involving aluminum oxide, also known as alumina. Some possibilities include:

  1. In the context of catalysts, deactivation of alumina could refer to the loss of catalytic activity over time due to various factors such as poisoning, sintering, or mechanical deformation. Catalyst deactivation can be caused by the accumulation of contaminants or by the reaction of the catalyst with the reactants or products.
  2. Deactivation of alumina could also refer to the removal of active sites or surface hydroxyl groups from the surface of the material. This process is often used to reduce the reactivity or surface area of the material, for example, to make it less prone to chemical reactions or to reduce its adsorption properties.
  3. In the context of ceramics or refractories, deactivation of alumina could refer to the deterioration or loss of performance due to exposure to high temperatures, mechanical stress, or chemical attack. This process can be caused by a variety of factors such as sintering, cracking, or corrosion, and can be prevented or mitigated through proper material selection, design, and use.

It is important to note that the specific process or treatment being referred to when discussing the “deactivation of alumina” will depend on the context in which the term is used.