AOAC GFA Stakeholder Program Meeting Book (March 15, 2023)

3.25 Sample The batch of matrix from which replicate test portions are removed for analysis. The sample contains analyte, if present, at one homogeneous concentration. “Sample” – the use of the term “sample” without modifiers should be deprecated and only allowed in rare circumstances. In any event, this definition appears to be similar to the AAFCO term for “Analytical Sample” which is the material from which the test portion is selected. I would recommend changing this definition to “Analytical Sample” and adding a definition for “Laboratory Sample” as per AAFCO GOOD Sample guidance document: Sample: A portion of a material selected from a larger quantity of material. The word “sample” should be used with a modifier as follows: Laboratory sample: The material received by the laboratory; Analytical sample: Results from any manipulation of a laboratory sample; Test Portion: The quantity of material taken for measurement. I prefer the terms as defined in the Quantitative Allergen document as they are consistent with the ones here. I would propose the definition here be replaced by what is in that document. “Sample” – The second sentence reads: “The sample contains analyte, if present, at one homogeneous concentration.” This sentence is problematic for several reasons. First, it is not necessary for the definition of the term. Second, this completely ignores the fact that there will always be some level of compositional and distributional heterogeneity in any sample. Measures should be taken to reduce these types of heterogeneity in the analytical sample - in fact the processing steps to go from Laboratory Sample to Analytical Sample and Test Portion should be designed for each matrix to reduce and control the heterogeneity to reasonable levels. The statement "at one homogeneous concentration" is not a good representation of current scientific perspectives on sampling and control of subsampling variation. Again see AAFCO documents.

COMMENTS CONTINUE ON NEXT SLIDE →