Karl Fischer titration: difference between revisions
Diff·revision 9 → 10·07:55, 13 Oct 2024
Difference between revision 9 and revision 10 of Karl Fischer titration. 2 lines changed; the page grew by 330 bytes.
| Revision 9 — 07:04, 27 Sep 2024 PBM_Perrin (talk) add the forced-degradation conditions the claim rests on 4,481 bytes +308 | Revision 10 — 07:55, 13 Oct 2024 Chromatokid (talk) expand §Chemical basis 4,811 bytes +330 | ||
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| 45 | For a research peptide vial nominally containing 5–10 mg of solid, only the coulometric variant is realistic: the total water present may be as little as 300 µg, which is below the practical resolution of a volumetric titration on that sample mass. Certificates reporting water content on 10 mg vials by volumetric titration should be read with that in mind.{{r|scholz1984}} | 45 | For a research peptide vial nominally containing 5–10 mg of solid, only the coulometric variant is realistic: the total water present may be as little as 300 µg, which is below the practical resolution of a volumetric titration on that sample mass. Certificates reporting water content on 10 mg vials by volumetric titration should be read with that in mind.{{r|scholz1984}} |
| 46 | 46 | ||
| + | 47 | {{note|Sample handling dominates the error budget. Lyophilised peptide is hygroscopic; a sample weighed in ambient laboratory air for two minutes can gain enough water to shift the result by a percentage point. Compendial procedure requires transfer under dry conditions, and reported values are only as good as that transfer.}} | |
| + | 48 | ||
| 47 | == References == | 49 | == References == |
| 48 | {{reflist}} | 50 | {{reflist}} |