Analysis of Uric Acid Concentration Using Immobilized Uricase and Catalase Columns Packed with Oxirane Acrylic Particle as Supporting Material

Uricase and catalase were immobilized on oxirane acrylic particle and packed into two separate columns which were connected in tandem. Each sample solution of uric acid, of concentration C and volume G, was injected into an inlet flow of 50 mM tris-borate buffer solution at pH 8.5 and 20°C flowing at the rate υ and the outlet flow was analyzed for its dissolved oxygen concentration by a dissolved oxygen sensor. Sensor output was integrated with respect to time to obrain S. Experimental results were as follows : 1) for the range of υ=7.6 to 15.3 cm3/min, C= 0.10 to 0.50 mg/cm3 and G=0.05 to 0.5 cm3, the relation S=151GC/υ, derived based on the stoichiometric relations, was found to hold, 2) an injection rate of sample solution higher than a certain value gave a value of S lower than the one expected, 3) activity of the uricase column was maintained stably for a period of 150 days, and 4) stochiometric correlation was observed between S and GC/υ for the two-column system. However, the proportionality between these two terms was also observed even in the case of absence of catalase column.