The effects of various classes of organic compounds and of metal ions on the catalytic activity of horseradish peroxidase in hydrogen peroxide-catalysed o-dianisidine oxidation and, on the activity of alkaline phosphatase in p-nitrophenyl phosphate hydrolysis have been studied. Enzymic methods have been developed for determination of sulphur compounds at 10−5−10−4M, nitrogen compounds at 2 × 10−7−3 × 10−5M mercury at 3 × 10−7 μ/ml and lead at 6 × 10−4 μ/ml concentration.

A bioluminescent method has been developed for creatine kinase (CK) assay using immobilized firefly extract containing the bioluminescent coimmobilized system: adenylate kinase + luciferase. ADP for the reaction with CK was produced from the initial mixture of AMP and ATP. The ATP formed in the reaction with CK was quantified using firefly luciferase. The lowest detection limit for CK activity was 0.5 ± 0.2 U/liter in the sample. A linear range of the determined CK activities was 0.5–1000 U/liter. The correlation coefficient between the bioluminescent and spectrophotometric methods was 0.981 (n = 40). The use of immobilized firefly extract for analysis has been shown to be advantageous compared to soluble enzyme.