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

PAGE FIVE – SELECTIVITY STUDY - BREADTH

Breadth The materials identified in Annex A, Table 1, should be tested at three times the LOQ of the method (as long as that is equal to or below 20 mg/kg, otherwise test at 20 mg/kg) in a rice flour matrix. Test six test portions per test material. The absorbance or optical density (OD) values for all test portions and standards must be reported. The extrapolated concentration for all test portions that had an absorbance or OD above the limit of detection of the method must be reported, and the percent recovery should be calculated and reported for each test portion. If any analysis is repeated, both datasets must be reported and a justification given for all repeat analysis. Calculate the mean recovery and 90% confidence interval for each gluten source.

Would like clarification on “calculate the mean recovery and 90% confidence interval for each (claimed) source.”