Reversed-phase HPLC is the preferred separation method for the
analysis of proteins and peptides, due to the superior resolution,
high theoretical plate number, good reproducibility, ease of use
and favorable cost performance.
In general, trifluoroacetic acid (TFA) is more often used as an
acid mobile phase, in the analysis of proteins and peptides.
However, reversed-phase HPLC using conventional silica gel shows
some degradation over time in these very acidic conditions. The COSMOSIL
AR-300 series packed columns have succeeded in improving acid
resistance due largely to the development of a new synthesis
method. It can be used for a longer time, while providing sharp
peak shape even in the concentrations of 0.1% of trifluoroacetic
acid.
Acid resistance
The COSMOSIL AR-300 series packed column show superior stability
in the following decomposition test under the strong acidic
conditions.
Capacity factor:
toluene, Mobile phase :60% methanol
Types
Three alkyl and one aromatic type stationary phases are
available in the COSMOSIL AR-300 series packed column.
Please consult the table and applications below for selection
guidance.
The sample loading capacity for protein or polypeptide
separations is proportional to the cross section of column inside
diameter. Using a short column, one can load a relatively large
quantity of sample due to the absorption and concentration of
sample inside the column. Below examples are shown for the
separation using COSMOSIL 5C
18-AR-300, with 4.6mmI.D. x 150mm column, 10mmI.D. x 150mm and
10mmI.D. x 250mm columns.
Identical separation patterns are achieved by adjusting
proportionally the flow rate and the sample injection volume to
the cross section of the column. There is little difference
between 10mmI.D. x 150mm column and 10mmI.D. x 250mm column. Thus,
semi-prep separations may be achieved using a shorter column.
Capacity factor:
toluene, Mobile phase :60% methanol
