AOAC GFA Stakeholder Program Meeting Book (August 27, 2023)

New and Enhanced Approaches

Limit of Quantification (LOQ) • Estimated based on observed precision in matrix studies (i.e., not only blanks or calibrants) • Notation to enhance communication o LOQ Definition: The lowest level of analyte in a test sample that can be reasonably quantified at a specified level of precision (ISO 5725-1:1994) o LOQ RSD : A limit of quantification with a specified relative standard deviation, expressed as a percentage (e.g., LOQ 10 , LOQ 20 ) o Allow for practical alignment between validation study results and test kit calibrants •  More empirical data to support LOQ estimates