REVERSE-FI INHIBITION-CHEMILUMINESCENCE DETERMINATION OF URIC ACID

The optimum conditions of the new chemiluminescence (CL) reaction system of oxidation of luminol by P-Mo-V-heteropoly acid in sodium hydroxide medium, and the inhibition of the CL emitted by the presence of uric acid were studied. It was found that the relative CL-intensity held a linear relationship with the concentration of uric acid in the range from 1.0×10~(-7) to 1.0×10~(-4)g per ml of solution, with a detection limit of (4×10~(-8)g·ml~(-1)). Test for its precision was made at the concentration level of 5.0×10~(-6)g·ml~(-1) for 11 successive determinations and the RSD obtained was 1.2%. A flow-injection installation with reverse flow device was described. The apparatus has been satisfactorily used in the determination of uric acid in urine samples.