ALUMINIUM OXIDE FOR COLUMN CHROMATOGRAPHY

Aluminium Oxide is currently the second most popular adsorbent in chromatography. It is a good all-purpose adsorbent and is commercially available in a variety of useful forms. There exists extensive literature on its chromatographic applications.

Like silica gel alumina may be regarded as a typical polar sorbent and the order of separation of compound classes in alumina and silica gel is generally similar. Carbon-carbon double bonds contribute somewhat more to compound adsorption energy on alumina as compared to silica gel, and hence compounds differing only in relative unsaturation (e.g. aromatic hydrocarbons) are generally better separated on alumina than on other polar adsorbents such as silica gel. Active aluminas are markedly sensitive to the differing shapes of various aromatic hydrocarbons and some of their derivatives permitting an excellent separation of many aromatic isomers.

The preferential adsorption of acidic substances on alumina offers many useful separation possibilities in the case of weak acids and this effect can be further enhanced by the use of basic solvents. Stronger acids however tend to chemisorb on alumina, requiring the use of acid treated aluminas. Acidic and neutral aluminas are useful for the separation of base sensitive materials. It should be noted that separation order maybe considered as distinct adsorbent subtypes.

ALUMINIUM OXIDE FOR COLUMN CHROMATOGRAPHY

	pH value	Wt. per ml approx.	Particle size
Basic	8.5 - 9.5	0.85 - 0.9 g.	100 - 300 mesh
Neutral	6.5 - 7.5	0.85 - 0.9 g.	100 - 300 mesh
Acidic	3.5 - 4.5	0.85 - 0.9 g.	100 - 300 mesh
Note: All the above types of Aluminium Oxide conform to Brockmann Activity grade I-II.

Applications:	In the separation and purification of dyes, dye intermediates, alkaloids, steroids, lipids, amino acids, hormones, aliphatic and aromatic hydrocarbons, vitamins and other pharmaceutical intermediates.
Note:	(1) Aluminas of any activity grade are available for plant or pilot-plant applications. (2) Activated alumina should be carefully protected from moist air at all times.