ELIMINATION OF INTERFERENCES IN FLOW-INJECTION AMPEROMETRIC DETERMINATION OF GLUCOSE IN BLOOD-SERUM USING IMMOBILIZED GLUCOSE-OXIDASE

A flow‐injection system with anodic amperometric detection for glucose determination in human blood serum samples was optimized by a comparison of various arrangements of enzyme immobilization and the elimination of interferences. The best results were obtained using a compact membrane biosensor in a wall‐jet, flow‐through detector with a platinum disk electrode covered with an evaporated Nafion layer, a polyester membrane with immobilized glucose oxidase, and another protective polyester membrane. In the optimized conditions, a linear response was observed up to 25 mM glucose with a detection limit of 200 μM glucose and a sampling rate of 120 samples/h for a 20 μL sample volume. Results of glucose determination in human serurn were compared with a Beckman Glucose Analyzer 2 and a Kone Dynamic analyzer. Copyright © 1990 VCH Publishers, Inc.