COSMOSIL<sup>®</sup> 3.0mm I.D. Columns Solvent saving economical columns

COSMOSIL® 3.0mm I.D. COLUMN was developed aiming at high sensitivity and the reduction of solvent requirement. This column is about twice as sensitive as the 4.6mm I.D. column. High performance packing material of the COSMOSIL® series is filled into the 3mm I.D. column by an original method. As a result high reproducibility is achieved for the separation of chelating compounds and basic compounds. In addition, it is not necessary to change the HPLC system,- a significant difference from the semi-micro bore columns! High sensitivity and the economical solvent consumption can be achieved on any ordinary HPLC system.
Material characteristics

5C18-MS-II 5C18-AR-II
Silica gel 5µm
Average pore size approx. 120Å
Specific surface area approx. 300m2/g
Stationary phase monomeric C18 group polymeric C18 group
End capping treatment near-perfect treatment
Carbon content approx. 16% approx. 17%


Comparison with 4.6mml.D. analytical column
COSMOSIL® 3.0mm I.D. column peak area is doubled compared with a conventional 4.6mm I.D. analytical column. As a result, the sensitivity doubles, and the amount of mobile phase and the waste fluid is about halved.

Influence of system dead volume on column performance
3.0mm I.D. column can be used with any conventional HPLC system without modification. However, theoretical plate number (N) decreases by 10-20% compared with 4.6mm I.D. column, which uses the same packing material.
The reason for the peak band diffusion phenomenon is the increase in the ratio of system dead volume to the volume of column. The 3.0mm I.D. column is excellent to minimize sample volume, save mobile phase and the waste fluid because of its sharp peak separation.
3.0mm I.D. column 4.6mm I.D. column
:micro HPLC system, x: standard HPLC system

The figure shows the relation between theoretical plate number and flow rate on 3mm I.D. column when conventional HPLC system and micro HPLC system are used. The 3mm I.D. column gives low theoretical plate number when connected to conventional HPLC system with big dead volume. On the other hand as Figure 2 shows the 4.6mm I.D. column is not influenced much by the difference of dead volume depending on the difference of HPLC system. Therefore, it is recommended to reduce dead volume of the system for 3mm I.D. column.
However, there is usually no problem even if ordinary system is used for most of the samples.

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Ordering information
Product name Size Code No. End-fitting
COSMOSIL® 5C18-MS Packed Column 3.0mmI.D.×150mm 38026-81 Waters type
3.0mmI.D.×250mm 38027-71
COSMOSIL® 5C18-MS-II Packed Column 3.0mmI.D.×150mm 34245-31
3.0mmI.D.×250mm 34254-11
COSMOSIL® 5C18-AR-II Packed Column 3.0mmI.D.×150mm 38028-61
3.0mmI.D.×250mm 38029-51


 
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