Certificate of analysis: difference between revisions
Diff·revision 20 → 21·10:29, 9 Apr 2025
Difference between revision 20 and revision 21 of Certificate of analysis. 2 lines changed; the page grew by 541 bytes.
| Revision 20 — 19:18, 26 Mar 2025 ChainCustodyChad (talk) correct the description of the sampling procedure 6,972 bytes ±0 | Revision 21 — 10:29, 9 Apr 2025 PancreasPru (talk) state that the sample was not drawn blind, so it represents the vial and not the lot 7,513 bytes +541 | ||
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| 51 | Where a purchaser obtains an independent determination on material from a lot and compares it with the certificate, agreement between the two establishes something narrow and worth being precise about: two measurements of the same sample agreed. It rules out a certificate written without measurement for that sample. It does not establish that the sample represents the lot, because the sample was chosen by the purchaser rather than drawn under a documented procedure — see [[Blind sampling]].{{r|iso17025}} | 51 | Where a purchaser obtains an independent determination on material from a lot and compares it with the certificate, agreement between the two establishes something narrow and worth being precise about: two measurements of the same sample agreed. It rules out a certificate written without measurement for that sample. It does not establish that the sample represents the lot, because the sample was chosen by the purchaser rather than drawn under a documented procedure — see [[Blind sampling]].{{r|iso17025}} |
| 52 | 52 | ||
| + | 53 | Disagreement is equally easy to over-read. Two laboratories running different gradients on different column chemistries, integrating valley-to-valley rather than by drop-line, and calibrating against different [[Reference standard|reference standards]], will produce different numbers for the same vial and both may be honest. This is why the '''method''' field matters more than its position on the page suggests: without it, a comparison between a certificate and a report is a comparison between two unspecified procedures.{{r|usp1503}} | |
| + | 54 | ||
| 53 | == References == | 55 | == References == |
| 54 | {{reflist}} | 56 | {{reflist}} |