Computer-assisted optimization of an immobilized-enzyme flow-injection system for the determination of glucose

✍ Scribed by C.L.M. Stults; A.P. Wade; S.R. Crouch

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 630 KB
• Volume: 192
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)85700-1

✦ Synopsis

A flow-injection system utilizing the Trinder reaction for the determination of glucose is designed and optimized. Glucose is converted to gluconic acid by passing it through a single-bead-string reactor (SBSR) onto which glucose oxidase enzyme has been immobilized. As it flows through a second SBSR, the gluconic acid reacts with a reagent stream of horseradish peroxidase, 4-aminoantipyrine and 3,5-dichloro-2-hydroxyphenyl sulfonate. The absorbance of the quinoneimine dye produced is then monitored at 510 nm in a flow-through cell. Optimum operating conditions were sought by using both univariate and Composite Modified Simplex procedures. Seven variables were considered. The performance of the system was improved by a factor of 22.5 relative to the starting conditions.

A calibration curve obtained at the optimum conditions was linear for O-3.3 mM glucose and usable for O-5.5 mM glucose. The optimization procedures revealed some interesting aspects of the Trinder reaction. Scatter diagrams generated from the simplex data showed definite trends for each of the seven variables. These are discussed.