AbstractFour reliable methods are described for the determination of ethoxyquin antioxidant in fresh fish meal. These include an accurate chromatographic laboratory method, a colorimetric method, and 2 rapid factory methods, one a quantitative titration technique and the other suitable for spot checks for ethoxyquin in “go—no go” situations. With the laboratory method, 6 or 8 Chromatographie columns can be handled simultaneously. The 2 rapid methods are based on l,l‐diphenyl‐2‐picrylhydrazyl and may be used routinely in the factory to determine the antioxidant content of several hundred samples.