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Silica Selection Guide

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SiliCycle offers a wide range of SiliaFlash products to cover many types of applications. Selecting the most appropriate sorbent for any given application can be difficult. To help you choose the right media (bonded or not), our experts recommend using the diagram below as a guide. Simply follow the three pathways to select the most suitable sorbent.

 

Selecting Pore Size

Sample molecular weight
(MW in Dalton)
Organic Molecules Peptides Proteins (Polypeptides)
Bio-polymers
MW < 1,000 Dalton 1,000 Dalton < MW < 10,000 Dalton MW > 10,000 Dalton
30, 40 Â (< 400 Dalton)
60, 70 Â (400 - 1,000 Dalton)
90, 100, 120, 150, 300 Â 500, 800, 1,000 Â

 

Selecting Particle Size

Generated Pressure (GP)
or Selectivity (α)
GP ≈ 950 psi (65 bar)
α < 1.2
(very difficult separation)
GP ≈ 220 psi (15 bar)
1.2 < α < 1.5
(difficult separation)
GP ≈ 73 psi (5 bar)
1.5 < α < 2
(possible separation)
GP ≈ 29 psi (2 bar)
α > 2
(easy separation)
From 0 to 30 µm From 15 to 40 µm From 40 to 100 µm From 40 to 1,000 µm

Selectivity (α) is measured by the retention factor ratio between similar compounds: α = Tr1 - T0
Tr2 - T0

 

A Particle Size for Each Application

This chart will help you select the right SiliaFlash irregular silica gel and particle size, depending on the targeted application.

Particle Size Distribution Application
Particles for Preparative TLC Plates
From 0 to 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)
Particles for Difficult Separations
From 10 to 45 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 distribution
  • Easier to pack and more uniform packing
  • Superior resolution
  • Suitable for use with complex matrices
60 - 120 µm
  • Alternative to 40-63 µm silica gel for faster flow rate with lower pressure
Particles for column (or Gravity) Chromatography
From 60 - 200 µm
  • Most economical silica for open column chromatography (gravity)
  • Suitable for very dirty purification
  • Easier to handle
120 - 200 µm
  • Silica for standard open column chromatography
  • Narrow particle size distribution enables uniform packing
  • Suitable for mass overload purification
Other Application
From 200 to 1,000 µm
  • Silica for plugs

See also:

 

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