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Packing Materials for reversed Phase Open Column Chromatography COSMOSIL C18-OPN

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Open column chromatography is an excellent and easy technique for large-scale preparation and purification at low cost. Normal phase conditions are traditional in open column chromatography. Recently several attempts have been made to apply reversed phase technique to open column chromatography because of its numerous advantages.
However the so far available reversed phase packing materials could not perform well over 30-50% water concentration in the mobile phase.
The COSMOSIL C18-OPN is not subject to such restrictions and the use of 100% aqueous effluents results in excellent separation. The COSMOSIL C18-OPN is a new type of reversed phase C18 packing material designed for open column chromatography.


The COSMOSIL C18-0PN packing material is coated with hydrophilic groups to improve the affinity for highly polar effluents. The hydrophobic groups in the pore of the packing material provide superior retention characteristics in reversed phase partition chromatography.
Material characteristics

75C18-OPN 140C18-OPN
Silica gel totally porous spherical silica
Average particle size 75m 140m
Average pore size approx. 120
Specific surface area approx. 300m2/g
Stationary phase octadecyl group
Application open column chromatography,s flash column chromatography
Reproducibility and washing methods
Wash the COSMOSIL C18-OPN packing material with tetrahydrofuran, chloroform or other solvents that can remove impurities absorbed onto the packing material. This packing material has excellent reproducibility and can be used repeatedly.

Do not wash with basic solvents of > pH 7 which will dissolve the silica gel or < pH 2 which will cleave the C18 stationary phase. Dry the packing material at 50C.

Influence of particle size
Comparison table of 75m and 140m
Particle ( m) Flow rate (ml/min) Theoretical plate number Rs Separation time(min) Consumption of solvent (ml)
75 0.25 400 390 340 1.00 1.74 240 60
140 0.60 300 280 260 0.90 1.40 100 60
Ordering information
COSMOSIL 75C18-OPN 37842-66 100g
37842-95 500g
37842-11 1kg
COSMOSIL 140C18-OPN 37878-16 100g
37878-45 500g
37878-61 1kg

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