This article discusses the effect of Rx silica, eXtra-Dense Bonding, and double end capping on peak shape, as well as the improved chromatographic performance of Eclipse XDB column packings for basic molecules (P and A) at neutral pH. By reducing the interaction of basic molecules with the packing surface, good peak shape is achieved. ZORBAX XDB-C8 exhibits better peak shape than Symmetry C8, even for the strongly basic molecule amitriptyline.
The document discusses High Performance Liquid Chromatography (HPLC) applications requiring mobile phases with a pH between 6 and 8. In this range, basic molecules become positively charged while silanols on the column packing ionize to become negatively charged, leading to peak tailing. To achieve the best quantitation and resolution, columns that minimize this tailing are recommended.
The text highlights that the Rx silica, eXtra-Dense Bonding, and double end capping features of Eclipse XDB column packings reduce the interaction of basic molecules with the packing surface. Consequently, these molecules chromatograph with good peak shape at neutral pH. The document compares the performance of ZORBAX Eclipse XDB-C8 against Symmetry C8, noting that the former shows better peak shape, even for strongly basic molecules like amitriptyline.
| Column Dimensions | 4.6 x 150 mm |
|---|---|
| Part Number | 993967-906 |
| Mobile Phase | 20mM Potassium Phosphate (pH 7.0): MeOH; 35:65 |
| Injection Volume | 20pL |
| Flow Rate | 1 mL/min |
| Detection | UV(254 nm) |
It reduces the interaction of basic molecules with the packing surface, allowing them to chromatograph with good peak shape at neutral pH.
Eclipse XDB-C8 shows better peak shape than Symmetry C8, even for the strongly basic molecule amitriptyline.