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绪言磷的比色測定利用两种显色反应:磷钼酸与磷钼釩酸銨的黄色反应和将磷钼酸还原为钼藍的藍色反应;后一反应的灵敏度較高,所以适合于比色測定。但是,在这一方法中还存在着一个严重的缺点,就是生成的钼藍顏色不够稳定,因此难以滿足比色分析上的要求,从而降低了方法的正确性。通过一些文献和实驗証明,钼蓝颜色不稳定的主要原因,是由于过量钼酸銨試剂的干扰反应和未能很好地控制适当的显色条件所引起。为
Introduction The colorimetric determination of phosphorus utilizes two color reactions: the yellow reaction of phosphomolybdic acid with ammonium phosphomolybdovanadate and the blue reaction of reducing phosphomolybdic acid to molybdenum blue; the sensitivity of the latter reaction is high and therefore suitable for Colorimetric determination. However, there is still a serious drawback in this method. The molybdenum blue color is not stable enough to meet the requirements of colorimetric analysis, which reduces the accuracy of the method. It has been proved by some literatures and experiments that the main reason for the unstable color of molybdenum blue is due to the interference reaction of excess ammonium molybdate reagent and the failure to properly control the proper color developing conditions. for