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过磷酸钙中磷的分析方法很多,有重量法、容量法,比色法、离子交换法等。每种分析方法又有几种操作方法。为配合实现农业四化对肥料分析的迫切要求,特就这些方法中最为简便而准确度可以满足要求的快速分析法作简单介绍。本快速法的原理是基于磷与钼酸铵作用生成磷钼酸铵,再用还原剂将其中的钼还原为四价钼而得蓝色的磷钼酸络合物[组成大致为(MoO_2·4MoO_3)_2·H_3PO_4]。在适当的pH或柠檬酸的存在下,硅不生干扰,As~(+5)发生相同的反应,但可用亚硫酸还原,V~(+5)与Fe~(+3)预先还原后
SSP phosphoric acid in many ways, there are gravimetric method, volumetric method, colorimetric method, ion exchange method. There are several methods of operation for each method of analysis. In order to meet the urgent needs of the four modernizations in fertilizer analysis, a brief introduction is given to the rapid analysis method which is most simple and accurate in these methods and meets the requirements. The principle of this fast method is based on the action of phosphorus and ammonium molybdate to generate ammonium phosphomolybdate, which is then reduced to tetravalent molybdenum by a reducing agent to obtain a blue phosphomolybdic acid complex [having a composition roughly (MoO 2 · 4MoO_3) _2 · H_3PO_4]. In the presence of appropriate pH or citric acid, Si does not interfere with the reaction, As ~ (5) the same reaction occurs, but available sulfur reduction, V ~ (+5) and Fe ~