Retention time: difference between revisions
Diff·revision 2 → 3·06:22, 5 Sep 2024
Difference between revision 2 and revision 3 of Retention time. 6 lines changed; the page grew by 634 bytes.
| Revision 2 — 21:17, 25 Aug 2024 PeakShapePol (talk) add the forced-degradation conditions the claim rests on 986 bytes ±0 | Revision 3 — 06:22, 5 Sep 2024 MoveRequestMio (talk) expand §Reporting on certificates 1,620 bytes +634 | ||
|---|---|---|---|
| 10 | It is not a property of the substance alone. Column chemistry and dimensions, mobile-phase composition, gradient profile, flow rate, temperature and even instrument dwell volume all change it, so a retention time is only meaningful alongside the conditions that produced it.{{r|usp621}} | 10 | It is not a property of the substance alone. Column chemistry and dimensions, mobile-phase composition, gradient profile, flow rate, temperature and even instrument dwell volume all change it, so a retention time is only meaningful alongside the conditions that produced it.{{r|usp621}} |
| 11 | 11 | ||
| + | 12 | == What it can identify == | |
| + | 13 | Matching a sample peak's retention to that of a [[Reference standard|reference standard]] run under identical conditions on the same day is the ordinary chromatographic identification. It is weak evidence on its own: many species can share a retention time on a given system.{{r|usp1503}} | |
| + | 14 | ||
| + | 15 | Co-injection strengthens it substantially. Spiking the sample with the standard should enlarge the existing peak without producing a shoulder; a shoulder indicates two species. | |
| + | 16 | ||
| 12 | == References == | 17 | == References == |
| 13 | {{reflist}} | 18 | {{reflist}} |
| 14 | <ref name="usp621">United States Pharmacopeia, General Chapter <621>, ''Chromatography''.</ref> | 19 | <ref name="usp621">United States Pharmacopeia, General Chapter <621>, ''Chromatography''.</ref> |
| + | 20 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> | |
| 15 | 21 | ||
| 16 | {{DEFAULTSORT:Retention time}} | 22 | {{DEFAULTSORT:Retention time}} |