Design and optimization of a flow-injection system for enzymatic determination of galactose

✍ Scribed by K.S. Kurtz; S.R. Crouch

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 690 KB
• Volume: 254
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(91)90027-3

✦ Synopsis

A flow-injection system for the determination of galactose has been designed and optimized. Galactose is oxidized in the flow-injection manifold via immobilized galactose oxidase to produce hydrogen peroxide. The hydrogen peroxide formed subsequently reacts with a leucomalachite green/peroxidase reagent, and the malachite green product is monitored spectrophotometrically at 620 nm. Optimal system conditions were investigated for both enzyme kinetics and reactor configurations. A Composite Modified Simplex routine was employed for multivariate optimization of five rate-dependent parameters. System factors considered in the Simplex optimization were sensitivity, precision, and sample throughput. The performance of the system was improved by a factor of 5.1 relative to initial conditions. Four immobilized enzyme reactor configurations were also investigated for their substrate conversion efficiencies and dispersion characteristics. Optimal system performance is attained by combining the results from the reactor design evaluations and the Simplex optimization. The galactose determination working range was 80 FM to approximately 2 mM for a 3Oql sample volume with an optimal sample throughput of 41 samples per hour. The relative standard deviation ranged from 0.02 to 2.45% over the galactose working curve.