Area percent purity: difference between revisions
Diff·revision 12 → 13·17:51, 19 Jan 2025
Difference between revision 12 and revision 13 of Area percent purity. 11 lines changed; the page grew by 685 bytes.
| Revision 12 — 16:38, 4 Jan 2025 FreightFenna (talk) add the reference standard and its traceability 5,314 bytes +245 | Revision 13 — 17:51, 19 Jan 2025 PBM_Perrin (talk) add the detection wavelength 5,999 bytes +685 | ||
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| 41 | ; Everything that was never dissolved : The determination is performed on the injected solution. Material that did not dissolve is not in it, so an appearance observation on reconstitution is a separate finding from a purity figure and has to be reported separately. | 41 | ; Everything that was never dissolved : The determination is performed on the injected solution. Material that did not dissolve is not in it, so an appearance observation on reconstitution is a separate finding from a purity figure and has to be reported separately. |
| 42 | 42 | ||
| + | 43 | === A worked example === | |
| + | 44 | A certificate reports 99.0% area percent for a 5 mg vial of a peptide. Suppose, as is ordinary for a lyophilised trifluoroacetate salt, that the vial also holds 5% water by mass and that trifluoroacetate accounts for 12% of the mass of the remaining solid. | |
| + | 45 | ||
| + | 46 | The peptide mass is then 5 mg × 0.95 × 0.88 = 4.18 mg, or 83.6% of the nominal fill. The purity figure of 99.0% is unaffected by either the water or the counterion, because neither is integrated in the chromatogram. Both figures are correct and they describe different things. | |
| + | 47 | ||
| 43 | == References == | 48 | == References == |
| 44 | {{reflist}} | 49 | {{reflist}} |
| 45 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, "Quality Attributes of Synthetic Peptide Drug Substances" (informational). USP–NF, current revision.</ref> | 50 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, "Quality Attributes of Synthetic Peptide Drug Substances" (informational). USP–NF, current revision.</ref> |
| 46 | <ref name="reports">Independent test reports and purchaser submissions held by PeptidePedia, 2024–2026, together with the analytical conditions supplied with them where any were.</ref> | 51 | <ref name="reports">Independent test reports and purchaser submissions held by PeptidePedia, 2024–2026, together with the analytical conditions supplied with them where any were.</ref> |
| + | 52 | ||
| + | 53 | == See also == | |
| + | 54 | * [[Peptide content]] | |
| + | 55 | * [[Certificate of analysis]] | |
| + | 56 | * [[Karl Fischer titration]] | |
| + | 57 | * [[Reference standard]] | |
| 47 | 58 | ||
| 48 | {{DEFAULTSORT:Area percent purity}} | 59 | {{DEFAULTSORT:Area percent purity}} |