AOAC ERP Gluten Assays - March 2019

Section I. Reading “Measure the Absorbance at 450 nm” Is there no subtraction of the blank of 600-630 nm? I think my reader does this automatically. Section J. Calculations No mention of preferred calibration model to be used. Use of non SI units – should be harmonized to mg/kg, not “mg gliadin /kg.” Sentence “Absorbance below standard 2 implies that the sample assayed is diluted too much or that no gliadin or gliadin below the LOQ is present in the sample.” This should be stricken pending a new analysis of LOD/LOQ. Sentence “This sample is considered to be gluten-free because the gluten concentration is below 20 mg/kg gluten.” Should be taken out – this is dependent on national regulation and should not be in the OMA method. Section on LOD/LOQ is not in alignment with the Abbott paper or current consensus of the ERP. The LOD/LOQ analysis should be redone.