Electrochemical enzyme cells for glutamate and aspartate analysis have been assembled and used in continuous-flow and in flow-injection analysis. The enzymes, glutamate oxidase (GOD) and aspartate amino-transferase (AST), were co-immobilized on an Immobilon Immuno-affinity membrane, which was placed into a three-electrode, flow-through cell. Additional protective membranes were used to reduce the electrochemical interferences and to protect the immobilized enzymes. Thin-layer and wall-jet cells were used and compared. Calibration curves for glutamate and aspartate showed a linearity range of 1-500 mumol/L and 10-500 mumol/L respectively. The sensitivity was higher using the flow-through system with a response time of 2 min. Better reproducibility was achieved using the FIA procedure with a response time of less than 1 min. Glutamate in foodstuffs and aspartate in some pharmaceutical products were analyzed. Results were compared and correlated well with an HPLC procedure.[...]
FLOW MONITORING OF GLUTAMATE AND ASPARTATE IN FOODS AND PHARMACEUTICAL PRODUCTS WITH IMMOBILIZED BIENZYME ELECTROCHEMICAL-CELLS
COMPAGNONE, DARIO;
1992-01-01
Abstract
Electrochemical enzyme cells for glutamate and aspartate analysis have been assembled and used in continuous-flow and in flow-injection analysis. The enzymes, glutamate oxidase (GOD) and aspartate amino-transferase (AST), were co-immobilized on an Immobilon Immuno-affinity membrane, which was placed into a three-electrode, flow-through cell. Additional protective membranes were used to reduce the electrochemical interferences and to protect the immobilized enzymes. Thin-layer and wall-jet cells were used and compared. Calibration curves for glutamate and aspartate showed a linearity range of 1-500 mumol/L and 10-500 mumol/L respectively. The sensitivity was higher using the flow-through system with a response time of 2 min. Better reproducibility was achieved using the FIA procedure with a response time of less than 1 min. Glutamate in foodstuffs and aspartate in some pharmaceutical products were analyzed. Results were compared and correlated well with an HPLC procedure.[...]I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
