Chain of custody: difference between revisions
Diff·revision 4 → 5·16:15, 8 Oct 2024
Difference between revision 4 and revision 5 of Chain of custody. 2 lines changed; the page grew by 259 bytes.
| Revision 4 — 05:50, 1 Oct 2024 ChainCustodyChad (talk) add the note that a purity figure without water and counterion is not a mass 2,414 bytes ±0 | Revision 5 — 16:15, 8 Oct 2024 BatchNumberBede (talk) clarify that a QR code on a certificate proves issuance, not content 2,673 bytes +259 | ||
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| 15 | For peptides, temperature and time are the conditions that matter most, because the degradation routes — [[Deamidation|deamidation]], [[Methionine oxidation|oxidation]], [[Peptide aggregation|aggregation]] — are all time- and temperature-dependent. A sample held at ambient temperature for three weeks before analysis may return a lower purity than the same material analysed on receipt, and without a record it is impossible to attribute the difference.{{r|usp1503,ich_q1a}} | 15 | For peptides, temperature and time are the conditions that matter most, because the degradation routes — [[Deamidation|deamidation]], [[Methionine oxidation|oxidation]], [[Peptide aggregation|aggregation]] — are all time- and temperature-dependent. A sample held at ambient temperature for three weeks before analysis may return a lower purity than the same material analysed on receipt, and without a record it is impossible to attribute the difference.{{r|usp1503,ich_q1a}} |
| 16 | 16 | ||
| + | 17 | This is the single most common confound in community testing. A result reported as characterising a supplier's material may be characterising the purchaser's storage, and the two are indistinguishable without a custody record. See [[Temperature excursion]]. | |
| + | 18 | ||
| 17 | == References == | 19 | == References == |
| 18 | {{reflist}} | 20 | {{reflist}} |