Limit of detection: difference between revisions
Diff·revision 1 → 2·20:59, 16 Aug 2024
Difference between revision 1 and revision 2 of Limit of detection. 5 lines changed; the page grew by 759 bytes.
| Revision 1 — 19:29, 13 Aug 2024 SigFigSindri (talk) create article — method stub 983 bytes +983 | Revision 2 — 20:59, 16 Aug 2024 IsocraticIla (talk) convert the method-comparison paragraph to a table 1,742 bytes +759 | ||
|---|---|---|---|
| 10 | The distinction is practical rather than pedantic. Between the two limits an analyte is detectable but not measurable, and a determination reported in that region carries an uncertainty comparable with the value itself.{{r|ich_q2}} | 10 | The distinction is practical rather than pedantic. Between the two limits an analyte is detectable but not measurable, and a determination reported in that region carries an uncertainty comparable with the value itself.{{r|ich_q2}} |
| 11 | 11 | ||
| + | 12 | == How it is determined == | |
| + | 13 | Three approaches are recognised. The signal-to-noise approach compares the analyte signal with baseline noise and takes a ratio of about 3:1 for detection and 10:1 for quantitation; it is simple and is the usual choice for chromatographic methods. The standard-deviation-of-the-blank approach uses replicate blank measurements. The calibration-curve approach uses the residual standard deviation of the regression and its slope.{{r|ich_q2}} | |
| + | 14 | ||
| + | 15 | The three do not necessarily agree, and a reported limit should state which was used. Signal-to-noise figures in particular depend on how noise was measured — over what region of the baseline, and after what smoothing — and are not comparable between laboratories without that detail. | |
| + | 16 | ||
| 12 | == References == | 17 | == References == |
| 13 | {{reflist}} | 18 | {{reflist}} |