Features of the Asahipak NH2P-50 Series Columns
- Suitable for saccharides analysis using HILIC mode
- Polymer-based packing material provides excellent chemical stability and minimum deterioration over extended time period
- Easily regenerated by washing in an alkaline solution
- Appropriate for evaporative light scattering detector, corona charged aerosol detector, and LC/MS
- Fulfills USP-NF L82 requirements
Same as packing materials for silica based amino columns, the packing material for Asahipak NH2P-50 columns has amino groups which are bonded to weak anion exchange resins.
The amino groups exist in the equilibrium of free type and acid type. (Please refer to the right figure.) The state of the equilibrium(free base ratio) depends on pH and ionic composition of the eluent.
To investigate the effect of free base ratio, NH2P-50 4E columns are equilibrated with ammonium acetate solvents of different pH to prepare columns of different free base ratio. Using the columns, analyses were performed under the same conditions. The result shows that the elution times became shorter and peak shapes became sharper as free base ratio increased.
| pH | 2.84 | 8.50 | 9.30 | Plate number vs Free base ratio |
|---|---|---|---|---|
| Free base ratio |
32% | 82% | 93% | |
| Chromato- gram |
 |
 |
 |
 |
