Reverse-phase HPLC: difference between revisions
Diff·revision 19 → 20·01:50, 1 May 2025
Difference between revision 19 and revision 20 of Reverse-phase HPLC. 5 lines changed; the page grew by 834 bytes.
| Revision 19 — 03:10, 7 Apr 2025 CiteBot (talk) bot: repair redlinked category 4,282 bytes +36 | Revision 20 — 01:50, 1 May 2025 Areapercent_Ayo (talk) split §Principle from §Practical limitations 5,116 bytes +834 | ||
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| 37 | Its limitations follow from the same properties. Very hydrophobic peptides retain strongly and may need a shorter alkyl chain or a higher organic proportion; acylated analogues such as [[Semaglutide|semaglutide]] fall into this class. Very hydrophilic peptides may not retain at all and elute in the void, where nothing is separated from anything.{{r|usp1503}} | 37 | Its limitations follow from the same properties. Very hydrophobic peptides retain strongly and may need a shorter alkyl chain or a higher organic proportion; acylated analogues such as [[Semaglutide|semaglutide]] fall into this class. Very hydrophilic peptides may not retain at all and elute in the void, where nothing is separated from anything.{{r|usp1503}} |
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| + | 39 | == Reading a reported determination == | |
| + | 40 | The fields that make a reverse-phase determination interpretable are the column (chemistry, dimensions, particle size), the mobile phases and modifier, the gradient profile and duration, the flow rate, the column temperature, and the detection wavelength. A certificate stating "purity by RP-HPLC: 99.1%" without them reports a number that cannot be reproduced or compared.{{r|usp621}} | |
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| + | 42 | Two further fields raise a determination substantially. Naming the retention time of the principal peak allows a subsequent determination to be checked for gross discrepancy. Itemising related substances individually, rather than aggregating them, shows how many species were resolved and at what level — which, as discussed at [[Limit of detection]], says as much about the method as about the material. | |
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| 39 | == References == | 44 | == References == |
| 40 | {{reflist}} | 45 | {{reflist}} |