分光光度计法测定复合肥料中有效磷含量

《GB/T 8573-2010复合肥料中有效磷的测定》的检测方法,是仲裁方法,该方法的缺点是的操作比较繁琐,抽滤需要的时间比较长,不能同时做多个样品;如果样品量较多的情况下,该方法有一定的局限性。本研究中试样经EDTA溶液提取,使磷在硝酸溶液中与钒钼酸铵生成黄色络合物,其颜色的深浅与磷的含量成正比,利用分光光度计测定吸光度进行定量分析。该方法操作步骤简单,需要的时间短,结果准确可靠,可以弥补国标方法的不足。

Determination of Available Phosphorus Content in Compound Fertilizers by Spectrophotometer

The detection method in ＂GB/T 8573-2010 Detection of available phosphorus in compound fertilizer＂ is an arbitral method, which has some disadvantages such as tedious operations, long time of suction filtration and especially unable to detect multiple samples simultaneously. In our study, samples were extracted by EDTA, some yellow complex can be formed trough the reaction of phosphorus and vanadium ammonium molybdate in nitric acid solution, and the intensity of the color is proportional with the phosphorus content, so that its absorbance can be measured with a spectrophotometer for quantitative analysis. The method has simple operation steps and needs short time; the result is accurate and reliable, which can make up for the deficiencies in national standard method.