POTENTIOMETRIC DETERMINATION OF GLUCOSE BY ENZYMATIC OXIDATION IN A FLOW SYSTEM

A potentiometric determination is described for glucose based on oxidation by 1,4-benzoquinone with immobilized glucose oxidase as catalyst in an enzyme reactor. The electrode is preceded by an analytical dialysis unit to remove proteins. The ratio of quinone to hydroquinone was measured with a flow-through gold electrode. Another gold electrode preceded the enzyme reactor to correct for serum components (e.g. ascorbic acid) which can also reduce quinone. The operating range is 0.04-10 × 10-3 M β-D-glucose. The dialysis proceeds with a linear dependence on glucose concentration, and the dialysis ratio can be adjusted by changing the buffer flow rate. © 1979.