MOOC: Validation of liquid chromatography mass spectrometry (LC-MS) methods (analytical chemistry) course

9. LoD and LoQ

This section addresses the performance parameters that are related to the ability of the method to detect, identify and quantify low analyte levels in samples:

  • Limit of detection () (also called detection limit) – the smallest amount or concentration of the analyte in the test sample that can be reliably distinguished from zero [].
  • Decision limit (CCα) – the concentration level, as determined by the method, at which there is a probability α (usually defined as 0.05 or 5%) that a blank sample will give a signal at this level or higher.
  • Detection capability (CCβ) – the concentration level of the analyte in the sample at which there is a probability β (again usually defined as 0.05 or 5%) that the method will give a result lower than CCα, meaning that the analyte will be declared as undetected.
  • Limit of quantitation () – the lowest concentration of the analyte that can be determined with an acceptable and .


 

9.1. Definitions and important aspects 

9.2. Decision limit and Detection capability

9.3. Estimating LoD 

9.4. Estimation of LoQ

All section 9 slides are downloadable in one file: