Simplified Method for the Determination of Ethoxyquin in Alfalfa Products and Mixed Feeds

Abstract

Abstract A simplified improved method for the determination of ethoxyquin in alfalfa products has been developed. It is based on the official AOAC photofluorometric method for ethoxyquin in animal feeds but eliminates some of the tedious steps encountered when that method is applied to ethoxyquin-treated alfalfa products. The extraction and phasic distribution steps are modified to simplify and make the method more reliable. A single total volume extraction with methanol and a single phasic distribution step with hexane are employed rather than successive partial volume extractions and partitioning steps. The increment technique is used in the fluorometric step to reduce possible errors caused by impurities which sometimes remain after phasic distribution in both methods. Results by the simplified method compare favorably with those by the official method and by a column chromatographic method for ethoxyquin. The method is also applicable to the determination of ethoxyquin in mixed feeds.