Retention time: difference between revisions
Diff·revision 4 → 5·05:57, 27 Sep 2024
Difference between revision 4 and revision 5 of Retention time. 4 lines changed; the page grew by 407 bytes.
| Revision 4 — 15:42, 18 Sep 2024 GroupBuyGalen (talk) state the mass accuracy in parts per million rather than daltons 1,620 bytes ±0 | Revision 5 — 05:57, 27 Sep 2024 SemaxSevi (talk) add the system-suitability criteria the method actually specifies 2,027 bytes +407 | ||
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| 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 | Relative retention time — the ratio of a peak's retention to that of a reference peak in the same run — is more robust, because system variations that shift both peaks cancel.{{r|usp1503,mant1996}} | |
| + | 13 | ||
| 12 | == What it can identify == | 14 | == 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}} | 15 | 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}} |
| ⋮ | ⋮ | ||
| 19 | <ref name="usp621">United States Pharmacopeia, General Chapter <621>, ''Chromatography''.</ref> | 21 | <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> | 22 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> |
| + | 23 | <ref name="mant1996">Mant CT, Hodges RS. "Analysis of peptides by high-performance liquid chromatography." ''Methods in Enzymology'' 271:3–50 (1996). PMID 8782429.</ref> | |
| 21 | 24 | ||
| 22 | {{DEFAULTSORT:Retention time}} | 25 | {{DEFAULTSORT:Retention time}} |
| 23 | [[Category:Chromatography]] | 26 | [[Category:Chromatography]] |
| 24 | [[Category:Analytical methods]] | 27 | [[Category:Analytical methods]] |
| + | 28 | [[Category:Analytical science]] | |
| 25 | 29 |