CHEMILUMINESCENCE DETERMINATION OF PROTEASES BY FLOW-INJECTION USING IMMOBILIZED ISOLUMINOL

A flow-injection system for protease determination is described. A tri peptide-isoluminol derivative was immobilized on an affinity support, and incorporated into the flow system, Injected enzyme sample solution s (0.025 cm(3)) catalysed the hydrolysis of some of the derivatives at pH 8.47, and the released isoluminol was detected by the chemilumines cence produced by its cobalt-catalysed oxidation with hydrogen peroxid e. Linear calibration results were obtained for alpha-chymotrypsin (fr om 5 x 10(-4) to 0.41 mg dm(-3)), trypsin (from 4 x 10(-2) to 4 mg dm( -3)) and a commercial protease (from 2 x 10(-3) to 4 mg dm(-3)), The l imits of detection were 2.7 x 10(-4), 4 x 10(-2) and 2 x 10(-3) mg dm( -3), respectively.