Enzyme reactors in unsegmented flow injection analysis

The design of immobilized-enzyme reactors for use in flow injection analysis is discussed. The reactors should be optimized for a short residence time and a very high (> 99.9%) conversion of substrate to products. Selection of carrier and immobilization method is important in order to increase the amount of active enzyme per unit volume. The effeciency of the reactor can be increased by decreasing the particle size in packed-bed reactors and the radius of open tubular reactors. The maximum inherent rate constant that can be obtained under optimal conditions is estimated for a number of enzymes of analytical interest; it is shown that with high rate constants and small particle diamters, residence times less than seconds can be obtained. Some applications of immobilized-enzyme reactors in flow systems are reviewed.