Reference standard: difference between revisions
Diff·revision 6 → 7·03:14, 30 Aug 2024
Difference between revision 6 and revision 7 of Reference standard. 4 lines changed; the page grew by 411 bytes.
| Revision 6 — 17:54, 20 Aug 2024 LotTraceLuka (talk) add the note on co-elution and what it hides 2,461 bytes +464 | Revision 7 — 03:14, 30 Aug 2024 DrTitration (talk) expand §Absence of standards in research supply 2,872 bytes +411 | ||
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| 17 | Assigned content is the field most often misunderstood. A standard is not pure in the colloquial sense; it is a material whose composition has been determined, so that a known mass of it contains a known mass of analyte. Calibrating against a standard while ignoring its assigned content introduces a systematic error of exactly the magnitude of the water and counterion it contains — for a [[Trifluoroacetate counterion|trifluoroacetate-salted]] peptide, often 15–30%. | 17 | Assigned content is the field most often misunderstood. A standard is not pure in the colloquial sense; it is a material whose composition has been determined, so that a known mass of it contains a known mass of analyte. Calibrating against a standard while ignoring its assigned content introduces a systematic error of exactly the magnitude of the water and counterion it contains — for a [[Trifluoroacetate counterion|trifluoroacetate-salted]] peptide, often 15–30%. |
| 18 | 18 | ||
| + | 19 | Because the assignment has an uncertainty, every quantitative result derived from it inherits that uncertainty. A content figure reported to four significant figures against a standard assigned to three is reporting precision it does not have.{{r|ich_q2}} | |
| + | 20 | ||
| 19 | == References == | 21 | == References == |
| 20 | {{reflist}} | 22 | {{reflist}} |
| 21 | <ref name="usp11">United States Pharmacopeia, General Chapter <11>, ''USP Reference Standards''.</ref> | 23 | <ref name="usp11">United States Pharmacopeia, General Chapter <11>, ''USP Reference Standards''.</ref> |
| 22 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> | 24 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> |
| + | 25 | <ref name="ich_q2">International Council for Harmonisation, ''Q2(R2): Validation of Analytical Procedures'' (2023).</ref> | |
| 23 | 26 | ||
| 24 | {{DEFAULTSORT:Reference standard}} | 27 | {{DEFAULTSORT:Reference standard}} |
| 25 | [[Category:Reference standards]] | 28 | [[Category:Reference standards]] |
| 26 | [[Category:Method validation]] | 29 | [[Category:Method validation]] |
| + | 30 | [[Category:Analytical science]] | |
| 27 | 31 |