Introduction

The selection of the particle size distribution and pore diameter for your application varies on the type of chromatography being done. In addition, not all the 40-63um gels are the same, i.e the absence of so-called fines (particles below 40um) has a great impact on performance.

Particle Sizes

The most popular particle size application and distributions are described hereafter.

5 – 20 µm

  • Contain neither binder (organic or inorganic) nor UV indicator (F254)
  • Can also be used in flash chromatography if higher resolution is required (higher back-pressure)
  • Specialized Particles for Difficult Separations: 15 – 35 µm

15 – 40 µm

  • High-resolution silica for difficult separations (similar polarities)
  • Particles for Flash Chromatography

40 – 63 µm

  • Chromatography types: high-resolution flash chromatography & low to medium-pressure preparative chromatography
  • Narrow particle size over other flash chromatography silica
  • Easier to pack
  • More uniform packing
  • Superior resolution
  • Suitable for uses with complex matrices

60 – 120 µm

  • Alternative to 40-63 µm silica gel for faster flow rate without pressure
  • Particles for column (or Gravity) Chromatography 60 – 200 µm
  • Most economical silica for open column chromatography (gravity)
  • Suitable for rough purification and large-scale preparative chromatography
  • Easier to handle
  • Purification cost reduction

120 – 200 µm

  • Silica for standard open column chromatography
  • Narrow particle size enables uniform packing
  • Suitable for mass overload purification

200 – 1000 µm

  • Silica for plugs

Pore Diameters

Typical pore sizes used for purification of different molecules depend on their molecular weight.

For small organic molecules with molecular weights Mw < 1.000 the typical pore sizes is 60 and 70A, for Mw < 400 40A. For peptides with Mw < 10.000 pore sizes 90-300A are applied and for polypeptides and bio-polymers with Mw > 10.000 typically pore sizes of 1.000A are applied.