摘要：Spectrophotometric determination of ultramicro amount of vanadium based on its catalytic effect in the oxidation of gallic acid has an advantage in rapidness and sensitivity. However, the catalytic method is seriously interfered by the coexistence of trace amounts of copper and iron ions in the sample, and the applicability of the method has been restricted. Therefore, addition of masking agents to improve the method was investigated, and addition of 1 ml of 0.1 M cyclohexanediaminetetraacetic acid (CDTA) solution to the sample almost eliminated the interference by copper and iron ions. In the proposed method, ppb levels of vanadium can be determined in the presence of diverse ions such as copperiron, lead, zinc, nickel, cadmium, chromium, sulfate, chloride, nitrate, etc., at their ppm concentrations. Application of the proposed method was tried for the analysis of vanadium in the water samples from river, swamp, underground water, and hot spring, and the concentrations of vanadium were found in the range of 0.1 to 10 ppb, and the recovery of vanadium was within 90 to 120%.
