This column is based on an ultra-pure silica gel (more than 99.99%) with carbon content of only 8.5%. Therefore the retention of polar compounds is relatively longer than that on the C18-MS-II or C18-AR-II. This column is also suitable for the analysis of a wide range of chemical compounds including polypeptides. 

Silica gel
high purity porous spherical silica
Average particle size
Average pore size
approx. 120Å
Specific surface area
approx. 300m²/g
Stationary phase
monomeric type octadecyl group
End capping treatment
near-perfect treatment
Carbon content
approx. 8.5%


Comparison data using different COSMOSIL ® C 18 columns

The COSMOSIL ® 5C 18 -P-MS gives quicker separation of most samples compared with other COSMOSIL ® 5C 18 type columns. However, there is a characteristic by which the polar compounds are retained relatively longer on the COSMOSIL ® 5C 18 -P-MS.

Separation of di-substituted benzene isomers

Because their characteristics (eg. polarity) and structure is very similar, isomers of di-substituted benzene are one of the most difficult samples to separate. It is possible to separate them at a high probability by using either any or a combination of three types of COSMOSIL ® C 18 (MS-II, AR-II, P-MS).



Cosmosil 5C18-P-MS Column


More resources on Carbon 60 Supplements at SES Research Inc.