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.
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
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 5C18-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.
Cosmosil 5C18 -AR-300 Column
5C18 -AR-300 – Semi-preparative Guard Column, 10 x 20 mm