High-performance liquid chromatography: difference between revisions
Diff·revision 23 → 24·09:47, 21 Jul 2025
Difference between revision 23 and revision 24 of High-performance liquid chromatography. 5 lines changed; the page grew by 612 bytes.
| Revision 23 — 15:04, 26 Jun 2025 ReceptorRhoda (talk) clarify the difference between related substances and total impurities 6,203 bytes ±0 | Revision 24 — 09:47, 21 Jul 2025 BlankVialBo (talk) add the cross-link to the compendial chapter 6,815 bytes +612 | ||
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| 47 | This is why a certificate that does not name its column, gradient, flow rate and detection wavelength cannot be compared with any other document or reproduced by any other laboratory. Method transparency is what converts a number into a checkable claim, and it is a more robust criterion for reading a certificate than the value of the number itself. It is also the precondition for the robustness assessment that validation requires. See [[Purity claim inflation]] and [[Analytical method validation]].{{r|usp1503,ich_q2}} | 47 | This is why a certificate that does not name its column, gradient, flow rate and detection wavelength cannot be compared with any other document or reproduced by any other laboratory. Method transparency is what converts a number into a checkable claim, and it is a more robust criterion for reading a certificate than the value of the number itself. It is also the precondition for the robustness assessment that validation requires. See [[Purity claim inflation]] and [[Analytical method validation]].{{r|usp1503,ich_q2}} |
| 48 | 48 | ||
| + | 49 | == Hyphenated and preparative variants == | |
| + | 50 | Coupling the column outlet to a mass spectrometer gives [[Liquid chromatography-mass spectrometry|LC-MS]], which adds mass information to retention information and converts a weak identification into a strong one. This is the ordinary way a peptide identity is confirmed.{{r|usp1503}} | |
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| + | 52 | Scaling the same separation up, with wider columns and higher loadings, gives [[Preparative HPLC purification|preparative HPLC]], which is a purification step rather than an analytical one. The chemistry is the same; the objective is collecting a fraction rather than measuring one. | |
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| 49 | == References == | 54 | == References == |
| 50 | {{reflist}} | 55 | {{reflist}} |