Detection Limit Rechner — Formel
## Limit of Detection and Quantitation
LOD is the lowest analyte concentration that can be reliably detected (S/N ≈ 3). LOQ is the lowest concentration that can be quantified with acceptable precision (S/N ≈ 10).
### Formulas (ICH Method)
**LOD = 3.3 × sigma / S** (often simplified to 3 × sigma / S)
**LOQ = 10 × sigma / S**
where sigma is the standard deviation of the blank response and S is the slope of the calibration curve. This is the most common approach in pharmaceutical and environmental analysis.
LOD is the lowest analyte concentration that can be reliably detected (S/N ≈ 3). LOQ is the lowest concentration that can be quantified with acceptable precision (S/N ≈ 10).
### Formulas (ICH Method)
**LOD = 3.3 × sigma / S** (often simplified to 3 × sigma / S)
**LOQ = 10 × sigma / S**
where sigma is the standard deviation of the blank response and S is the slope of the calibration curve. This is the most common approach in pharmaceutical and environmental analysis.
Lösungsbeispiel
Blank standard deviation = 0.005, calibration slope = 2500 signal/M.
- LOD = 3 × 0.005 / 2500 = 0.015 / 2500 = 6.0 × 10⁻⁶ M = 6.0 uM
- LOQ = 10 × 0.005 / 2500 = 0.05 / 2500 = 2.0 × 10⁻⁵ M = 20 uM