FLOW-INJECTION ANALYSIS SYSTEMS WITH IMMOBILIZED ENZYMES - IMPROVEMENT OF APPLICABILITY BY INTEGRATION OF COUPLED REACTIONS, SEPARATION STEPS AND BACKGROUND CORRECTION

The specificity of enzymes is often not sufficient to simultaneously d etermine two parent substrates in a given matrix. Approaches to enhanc e the selectivity by applying the principle of an array arrangement to flow-injection analysis (FIA) systems based on several immobilized is oenzymes are successful. Immobilized enzymes and detectors in FIA syst ems often suffer from interferences from impurities of the matrix. Exa mples are given which prove that this problem can be overcome by an in tegrated preseparation of the analyte (pervaporation, electrodialysis) or by correction of the matrix signal based on background subtraction using computerized data accumulation and processing.