Determination of 1-Lysine in Feeds by Fluorometric Method Based on 1-Lysine Oxidase

Abstract
Feeds or feed stuffs were hydrolyzed by acid to liberate 1-lysine. Homovanillic acid, peroxidase and 1-lysine oxidase were used to produce the fluorescence substance corresponding to 1-lysine. A computerized fluorometer was used for the measurement (up to 0.7 mg/1 of 1-lysine in the optical cell) and the time required for the measurement was about 1 min. The reproducibility was 1.0% in CV. Recovery tests and comparative tests against the conventional method were carried out. The effects of various experimental conditions on the fluorescence response were discussed.