Flow Injection Determination of Lactate Using Immobilized Lactate Dehydrogenase Enzyme with Tris(2,2′-Bipyridyl)Ruthenium(III) Chemiluminescence Detection

Abstract

ABSTRACTA flow-injection procedure is reported for the determination of L-lactate based on its enhancement on tris(2,2′-bipyridyl)ruthenium(III) chemiluminescence in the presence of reduced nicotinamide adenine dinucleotide produced using immobilized lactate dehydrogenase. The calibration graph was linear between 4 and 50 × 10−7 mol L−1 (r2 = 0.9998) with relative standard deviation from 1.6 to 3.0% (n = 4). The limit of detection was 1 × 10−7 mol L−1 with a sample throughput of 60 per hour. The effect of common organic compounds and metal ions was studied. The immobilized lactate dehydrogenase exhibited good operational activity at 37°C for one week and storage stability at 4°C over a period of 10 weeks. The method was applied to blood serum, and the results were in good agreement with those obtained by a conventional spectrophotometric method with no significant difference at the 95% confidence level.