AOAC GFA Working Group Documents for Review (November 2022)

Making Rinse Water/CIP/Cleaning Solution Study Samples Make a high level suspension of gluten in kit extraction buffer or 60% ethanol, then dilute into water or water/cleaning solution to the desired gluten concentrations, around the expected sensitivity level of the method, as described in the validation requirements. The high level gluten solution in kit extraction buffer or ethanol should not make up more than 1% of the final CIP (cleaning solution)/rinse water preparation, to ensure that the sample is representative of a typical CIP (cleaning solution)/rinse water sample. If the method is designed for rinse water testing, and the cleaning solution will not be tested at its recommended working concentration, the dilution of the cleaning solution must be reported. Cleaning solution (CIP) validations must be performed separately for each cleaning agent. Method developers may choose to perform a validation in examples from each of the four main types of cleaning solutions: degreasers, detergents, abrasives, and acids. But the validation will only be reported for the specific cleaning agent that is used.

Figure 1. Options for generating bulk spike materials at various levels