DETERMINATION OF L-LACTATE BY DIFFERENTIAL PULSE POLAROGRAPHY WITH COVALENTLY IMMOBILIZED ENZYME ON CHITOPEARL

The covalent bonding of L-lactate oxidase (no E.C.) to cross-linked copolymers of chitosan (Chitopearl) using the glutaraldehyde method is described and applied to the determination of L-lactate in serums of diseased and normal animals. The bioreactor packing of the immobilized enzyme is stable for at least 4 months and can be continuously used for the rapid and simple determination of L-lactate. The reduction current of pyruvate, corresponding to the product of enzymatic reaction, is determined by differential pulse polarography. The reproducibility (RSD) for 10 mu-mol/1 L-lactate is 0.78% (n = 6) and the detection limit is 0.62 mu-mol/1 (k = 2, confidence level 97.72%).