AOAC Guidance on FA Immunoassay Validation (August 2023)

3.2.5. LOQ RSD : A limit of quantification with a specified relative standard deviation, expressed as a 141 percentage. For example, an LOQ 10 from a single laboratory validation would be the concentration 142 where the RSD i = 10%. In the case of an LOQ RSD estimated from a collaborative study, an LOQ 30 would 143 be the concentration where the RSD R = 30%. 144 3.2.6. Measurement range: the concentration range over which the target analyte can be reliably 145 quantified/detected 146 3.2.7. Recovery: The fraction or percentage of analyte that is recovered when the test sample is 147 analyzed using the entire method 148 3.2.8. Precision: Closeness of agreement between independent test/measurement results obtained 149 under stipulated conditions. (ISO 3534-2:2006) 150 3.2.9. Repeatability: Precision under repeatability conditions. (ISO 3534-2:2006). (Repeatability 151 Conditions: Observation conditions where independent test results are obtained with the same 152 method on equivalent test items in the same laboratory by the same operator using the same 153 equipment within short intervals of time. (ISO 3534-2:2006, with minor modifications) 154 3.2.10. Reproducibility: Precision under reproducibility conditions (ISO 3534-2:2006). (Reproducibility 155 Conditions: Observation conditions where independent test results are obtained with the same 156 methods on equivalent test items in different laboratories with different operators using different 157 equipment. (ISO 3534-2:2006, with minor modifications)) 158 3.2.11. Intermediate precision: precision under intermediate conditions (ISO 3534-2). (Intermediate 159 precision conditions: conditions where test results or measurement results are obtained with the 160 same method, on identical test/measurement items in the same test or measurement facility, 161 under some different operating condition.) 162 3.2.11.1. Note 1 to entry: There are four elements to the operating condition: time, calibration, 163 operator and equipment. 164 3.2.11.2. The specific and minimum conditions applicable for validation of food allergen 165 immunoassays are described in section 5.2.4.2.2 166 3.2.11.3. For the purposes of this document, the subscript notation "i" will be used to indicate terms 167 and estimators associated with intermediate precision. Estimation methods can be found in 168 section 5.2.4.2.3. 169 3.3. Qualitative Methods 170 3.3.1. Probability of detection (POD) : The proportion of positive analytical outcomes for a qualitative 171 method for a given matrix at a given analyte level or concentration. POD is concentration 172 dependent. 173 3.3.2. Claimed Detection Capability (CDC): An analyte concentration that demonstrates a POD of at least 174 0.90, with 95% confidence. This may be estimated across all matrices, or individually per matrix. 175 The claimed detection capability must be verified empirically during method validation. 176 3.3.3. Fractional recovery: Validation criterion that is satisfied when an unknown sample yields both 177 positive and negative responses within a set of replicate analyses. (5) 178 3.3.4. Lateral flow device (LFD): an analytical method characterized by use of an 179 immunochromatography platform for detection of specific target analytes 180 3.3.5. LPOD: composite POD pooled across laboratories. (6) 181