MT 145 - Active ingredients containing phosphorus
Content Handbook F
Ouline of method
The method is applicable only if the substance to be determined can be separated from other components of the sample by TLC in such an amount that the area of the silica gel layer used for the determination contains approximately 200-400 ìg of phosphorus.
The substance to be determined is separated from manufacturing impurities and added modifying agents by TLC on aluminium foils coated with silica gel. The area containing the active ingredient is cut out and the active ingredient is converted to inorganic phosphate with sulphuric acid and hydrogen peroxide. The phosphate formed is determined colorimetrically as the molybdovanado complex.
The procedure described in this method is applicable to pesticide products, technical and formulated materials, containing phosphorus which is convertable to orthophosphate by sulfuric acid-hydrogen peroxide digestion.