适用于含磷量超过0.0005%（m/m）的产品。用碳酸钠和硼化物的混合物或碳酸钠和四硼酸钠的混合物，通过碱熔从试验部分制备溶液。在硝酸中溶解冷却的熔融物质，并将适当的等分部分调节至pH 2。磷钼络合物的形成和2-甲基丙烷-1-醇在硫酸介质中的萃取。通过有机相中的稀（II）氯化物还原络合物，并在约730 nm波长下分光光度法测量还原络合物。也得到了IUPAC的批准。

Applicable to products having phosphorus contents of more than 0.0005 % (m/m). Preparation of a solution from a test portion by alkaline fusion either with a mixture of sodium carbonate and borid or of sodium carbonate and sodium tetraborate. Dissolution of the cooled molten mass in nitric acid and adjustment of an appropriate aliquot portion to pH 2. Formation of a phosphomolybdic complex and extraction by 2-methylpropan-1-ol in a sulphuric acid medium. Reduction of the complex by thin(II) chloride in the organic phase and spectrophotometric measurement of the reduced complex at a wavelength of about 730 nm. Has also been approved by the IUPAC.