Silica Gel Column Chromatography

Silica gel column chromatography has found its place in many laboratories for reaction control in organic syntheses and preparation purposes. Column chromatography has gained wide appreciation for simple packing procedure, low operating pressure and low expense for instrumentation. Depending on flows of solvent down the column chromatography is separated into two categories :
Solvent flow down the column by gravity, or percolation, it is called gravity column chromatography .
Solvent is forced down the column by positive air pressure, it is called flash
Chromatography Organic chemist use two common adsorbents silica gel (SiO2) and alumina (Al2O3) for column chromatography.
These adsorbents are sold in different mesh sizes, as indicated by a number on the bottle label. Adsorbent particle size affects how the solvent flows through the column. Smaller particles (higher mesh values) are used for flash chromatography; larger particles (lower mesh values) are used for gravity chromatography. For example, 70, 230 silica gels are used for gravity columns and 230, 400 mesh for flash columns.
Grades Available :

• 35-70 mesh
• 60-120 mesh
• 70-230 mesh
• 100-200 mesh
• 200-400 mesh
• 230-400 mesh
• 400-800 mesh