Aluminium Oxide is one of the most versatile sorbents for preparative chromatography. Due to its amphoteric character, Aluminium Oxides can be used in specifically defined pH ranges.
CAMAG manufactures the various types of Aluminium Oxide, which are used in the following purification processes:
Preparative Column Chromatography
is a widely used technique to separate and purify API’s (Active Pharmaceutical Ingredient) from lab scale to pilot plant and up to production scale in large columns under hydrostatic or low pressure. Since the Aluminium Oxides are of a wide particle size range, packing techniques must insure that segregation does not occur. This is best accomplished by dry packing, then equilibrating the alumina with the solvent to be used for the separation. If wet packing is done, it must be done with a thick mud-like slurry.
Flash Chromatography
is a rapid form of preparative column chromatography. Prep LC based upon «an air pressure driven hybrid of medium and short column chromatography optimized for rapid separation». Flash chromatography is typically used when the differences on TLC are greater than 0.15 Rf units. Flash Chromatography is a simple and economical approach to Prep LC.
Selective filtration
is done by feeding the contaminated solvent extract through a short bed of Aluminium Oxide in large column systems which are run under vacuum, hydrostatic or gas pressure. Two typical modes are found: ‹Frontal Elution› or ‹Solid Phase Extraction›. ‹Frontal Elution› of the extract is commonly used when the extract is complex and/or colored. The extract is fed through a bed of Aluminium Oxide while the decolorized product is collected. Solid Phase Extraction of the mixture is preferred when the product is highly diluted. The product is selectively bound to Aluminium Oxide and eluted in a small volume after saturation of the matrix.