LOD and LOQ Calculator
Estimate the limits of detection and quantitation from a low-level calibration curve, and check signal-to-noise.
- ICH Q2(R2)
- Residual SD or SD of intercept
- S/N = 2H/h
- No sign-up
Four steps, or fewer
- Choose how σ is estimated.
- Paste a calibration curve close to the expected limits, not the full assay range.
- Optionally enter peak height and noise for the signal-to-noise check, then confirm the LOQ experimentally.
Not sure what to enter? Press Load example to see the calculator with realistic data. Your inputs are saved in this browser, so they are still there when you come back.
How LOD and LOQ are estimated
S = slope of the calibration curve
σ = residual SD of the regression, or SD of the y-intercept
S/N = 2H / h (Ph. Eur. 2.2.46)
Signal-to-noise ratios of about 3:1 (detection) and 10:1 (quantitation) are generally accepted. A calculated LOQ must be confirmed by analysing samples at that concentration with acceptable precision and accuracy.
References
- ICH Q2(R2) Validation of analytical procedures
- Ph. Eur. 2.2.46 Chromatographic separation techniques
These calculators are decision support for orientation and training. They are not validated GMP software, and results must be checked against your approved method, SOP and the current pharmacopoeia or guideline before use in GMP records. Your data is processed in your browser and is not sent to Molgenium.