Preparative HPLC purification: difference between revisions
Diff·revision 4 → 5·04:46, 4 Sep 2024
Difference between revision 4 and revision 5 of Preparative HPLC purification. 2 lines changed; the page grew by 280 bytes.
| Revision 4 — 09:39, 28 Aug 2024 MelanocortinMil (talk) space between number and unit per PP:MOS 1,990 bytes +624 | Revision 5 — 04:46, 4 Sep 2024 MetricMabel (talk) add the reconstitution-stability sentence with its storage condition 2,270 bytes +280 | ||
|---|---|---|---|
| 10 | The governing trade-off is yield against purity. Collecting a narrow window around the peak apex gives high purity and discards a substantial fraction of the product; collecting more widely recovers more material and includes more of the shoulders where impurities elute. Where the cut is made is a commercial decision as much as a technical one.{{r|mant1996}} | 10 | The governing trade-off is yield against purity. Collecting a narrow window around the peak apex gives high purity and discards a substantial fraction of the product; collecting more widely recovers more material and includes more of the shoulders where impurities elute. Where the cut is made is a commercial decision as much as a technical one.{{r|mant1996}} |
| 11 | 11 | ||
| + | 12 | Because peptide impurities are structurally similar to the peptide, they elute close to it, and the separation problem grows harder as the target purity rises. The difference in cost between 95% and 99% material is not proportional to the difference in the numbers.{{r|usp1503}} | |
| + | 13 | ||
| 12 | == Scale-up == | 14 | == Scale-up == |
| 13 | Moving from analytical to preparative scale increases column diameter and loading while keeping the chemistry constant. Linear velocity is preserved rather than volumetric flow, so flow rates rise with the square of the diameter, and mobile-phase consumption rises with them — the dominant recurring cost.{{r|mant1996}} | 15 | Moving from analytical to preparative scale increases column diameter and loading while keeping the chemistry constant. Linear velocity is preserved rather than volumetric flow, so flow rates rise with the square of the diameter, and mobile-phase consumption rises with them — the dominant recurring cost.{{r|mant1996}} |