CHEMILUMINOMETRIC L-LYSINE DETERMINATION WITH IMMOBILIZED LYSINE OXIDASE BY FLOW-INJECTION ANALYSIS

An enzymatic flow-injection procedure for the determination of L-lysine was developed. A lysine oxidase reactor is combined with a fibre-optic hydrogen peroxide detector. Hydrogen peroxide detection is based on the peroxidase-catalysed luminol reaction. The chemiluminescent light is detected by a photomultiplier. L-Lysine can be determined in the range 10-1000 muM. A sampling rate of up to 90 h-1 can be achieved. The whole sensing assay works for more than 1 month. The double logarithmic graph of the peak signal height vs. the lysine concentration is linear, the slope being larger than unity (r2 = 0.991, n = 4).