Purification

Adsorbents for use as Purification Media

Sigma-Aldrich's polymeric resins portfolio is further complemented by a broad range of inorganic adsorption media, for a wide variety of purification applications. Our offering of inorganic adsorption media includes:

  • Bare silica
  • Silica, bonded, e.g. C18, C8, aminopropyl, chloropropyl, etc.
  • Lipid Removal Agent (LRA®)
  • Florisil® magnesium silicate
  • Activated alumina
  • Celite® and Celite Analytical Filtration Aid (CAFA II)
  • Carboxen™ and carbon molecular sieves (CMS)
Inorganic Adsorbent Selection (see our Carbon Adsorbent Selection Guide for Carboxen and CMS)
Type Brand Comments
Bare Silica Merck KGaA Merck® silica gels are widely used for column chromatography. They are very pure and consistent materials (iron <0.02% and chlorine <0.02%). These products demonstrate consistent particle size and defined pore structure.
Davisil® Davisil silica gels are available in various particle and pore sizes for preparative column chromatography. They have been processed to minimize or eliminate impurities such as minor metallic oxides which can modify the surface and unpredictably alter adsorption processes.
Sigma-Aldrich® Sigma-Aldrich offers a complete line of high purity silica gels that equal or exceed the specifications of silicas offered by Merck and Davisil. Additionally, we offer a line of economy-minded silicas that provide excellent performance at a lower cost.
Modified/
bonded silica
Sigma-Aldrich The surface polarity of silica gel is dramatically modified by chemically bonding it with organosilane groups. This treatment produces chromatographic media with unique separation properties. Use of functionalized silica can complement bare silica allowing alternative resolution or separation of difficult compounds. It is generally used on a sample cleanup, bulk, or preparative basis.
Lipid Removal Agent (LRA)
(100g / 500g)
Sigma-Aldrich LRA media is a synthetic calcium silicate hydrate (composition: 32% calcium oxide, 48% silicon dioxide, and residual levels of sodium, magnesium, and iron). It can be used in sample preparation and solid phase extraction.
Celite Sigma-Aldrich Celite is an acid washed, high purity, flux calcined, diatomaceous silica that is specially produced for chromatography and other laboratory applications as a filter aid. Celite 545 AW is purified for chromatography.
Florisil Sigma-Aldrich Florisil adsorbents are used in preparative and analytical chromatography, and are available in pesticide-residue (PR) and standard grades, in powdered and granular forms. All grades are activated and have a surface area of 300 m2/g and a pH of 8.5.
Activated
alumina
Sigma-Aldrich Activated alumina is a highly porous and adsorptive media with surface area approaching 200 m2/g. Alumina is commonly used for purification of chromatographic and synthetic chemicals, and for extraction of pollutants. We offer four types of activated alumina (Al2O3) designed for column chromatography: acidic, weakly acidic, basic, and neutral. All grades have a Brockmann activity of I.

For additional information, please contact techservice@sial.com.
Trademarks: Davisil – W.R. Grace & Co.-Conn.; LRA – Advanced Minerals Corporation; Merck – Merck KgaA; Florisil – U.S. Silica Company; Celite – Celite Corp.; Carboxen, Sigma-Aldrich – Sigma-Aldrich Co. LLC.