Preparative HPLC purification: difference between revisions
Diff·revision 3 → 4·09:39, 28 Aug 2024
Difference between revision 3 and revision 4 of Preparative HPLC purification. 5 lines changed; the page grew by 624 bytes.
| Revision 3 — 22:34, 15 Aug 2024 CrudePeptidePearl (talk) add the note that lyophilised material tolerates excursions better than solution 1,366 bytes ±0 | Revision 4 — 09:39, 28 Aug 2024 MelanocortinMil (talk) space between number and unit per PP:MOS 1,990 bytes +624 | ||
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| 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 | == 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}} | |
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| + | 15 | Loading is limited by overload. As the mass injected rises, peaks broaden and distort and resolution falls, so the practical loading is set by how much distortion the required purity tolerates. Touching-band operation, in which adjacent peaks just meet, is the usual economic optimum. | |
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| 12 | == References == | 17 | == References == |
| 13 | {{reflist}} | 18 | {{reflist}} |