AOAC Gluten Quantitative Validation Guidance-Round 1(Nov 2023)

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3.14 Intermediate precision:

Precision under intermediate conditions (ISO 3534-2). For the purposes of this document, the subscript notation "i" will be 134 used to indicate terms and estimators associated with intermediate precision. Estimation methods can be found in section 4.6 135 3.15 Intermediate precision conditions: 136 Conditions where test results or measurement results are obtained with the same method, on identical test/measurement 137 items in the same test or measurement facility, under some different operating condition, which may include, but are not limited 138 to: time, calibration, operator, reagent lots and equipment. 139 Specific criteria for intermediate precision conditions are given in section 4.4 140 3.16 Limit of detection (LOD): 141 The lowest concentration or mass of analyte in a test material that can be distinguished from a true blank test material at a 142 specified probability level (ISO 5725-1:1994). See further details on how to determine LOD in section 6.5. 143 3.17 Limit of quantification (LOQ): 144 The lowest level of analyte in a test portion that can be reasonably quantified at a specified level of precision (ISO 5725- 145 1:1994). See further details on how to determine LOQ in section 6.6 146

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3.18 LOQ RSD :

A limit of quantification with a specified intermediate precision relative standard deviation, expressed as a percentage. For 148 example, an LOQ 10 from a single laboratory validation would be the lowest concentration where the RSD i = 10%, and the LOQ 10 149 from a collaborative study would be the lowest concentration where the RSD R = 10%. 150

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3.19 Matrix:

152 environmental surface material to be included in the validation as per the intended use of the method. 153 3.20 Measurand: 154

Totality of components of a material system except the analyte (ISO 17511). For example, the food, beverage, or

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The quantity intended to be measured (the specification of the measurand should be sufficiently detailed to avoid any

ambiguity). See also “analyte” definition.

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3.21 Measurement interference:

A cause of significant bias in the measured analyte concentration due to the effect of another component or property of the 158 sample which may result from non-specificity of the detection system, suppression of an indicator reaction, or inhibition of the 159 analyte. (CLSI guideline EP07-A2) An interference can be endogenous, present in the sample, or exogenous, introduced into the 160 sample during the measurement process. 161 3.22 Measurement range: 162 The concentration range over which the target analyte can be reliably quantified/detected 163 3.23 Precision: 164 The closeness of agreement between independent test results under stipulated conditions. (ISO 5725-1). 165 3.24 Qualitative method: 166 Method of analysis whose response is either the presence or absence of the analyte. 167 3.25 Quantitative method: 168 Method of analysis whose result is the amount (mass or concentration) of the analyte. 169 3.26 Recovery: 170 The fraction or percentage of analyte that is recovered when the test portion is analyzed using the entire method 171 3.27 Reference material: 172 Material, sufficiently homogeneous and stable with respect to one or more specified properties, which has been established 173 to be fit for its intended use in a measurement process (See NIST SRM Definitions} 174 3.28 Repeatability: 175 Precision under repeatability conditions. (ISO 5725-1). 176