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

4.1.2 Selectivity study Interference The matrices identified in Annex A, Table 2 will be spiked with gluten from each claimed gluten source at 20 mg/kg (or less, depending on the regulatory threshold of the target market/country), or two times the environmental surface detection limit for methods limited to environmental surface testing. Sample preparation is described in Annex B. The prepared samples/surfaces will be analyzed with the candidate method as it is designed. Test one replicate per sample. For each sample, the method should produce a positive result. In the event that the single sample replicate tests negative, it may be retested in 20 biological replicates, with no failures allowed, to rule out interference. Findings that certain matrices interfere with gluten detection should be investigated further, using additional similar matrices, to determine the full scope of interference. Unless the interference can be shown to be limited to very few and specific matrices, and this claimed limitation would be of no concern to the method’s end users, this type of interference may not meet the requirements for validation. Any interfering matrices must be reported in the method instructions.

The sentence "Unless the interference can be shwin to be limited to very few and specific matrices....this type of interference may not meet the requirements for validation" means what? What are the consequences?