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.
:micro
HPLC system, x: standard HPLC system
