Determination of phosphorus content of the alkyl amido phosphate ester by ammonium vanadate-molybdate spectrophotometric method

General phosphorus content of the alkyl amido phosphate ester is determined by ammonium vanadate-molybdate spectrophotometric method. The effect of determined wavelength,mixture proportion and amount of (oxidant,amount of) concentrated sulfuric,colour time,weight of sample on determined results is examined.The optimum determined conditions are as follows:Determined wavelength is 460 nm,V(HNO_3)∶(V(HClO_4)=1∶1～3∶1, amounts of oxidant,)mixed reagent and concentrated sulfuric acid are 4 mL, 5 mL,(6 mL respectively,)colour time is 15 min～20 min and weight of sample is 0.1 g～0.2 g.The average relative error of determined results is 0.0476% in the aforesaid conditions.This method can be used for quantitative analysis of the alkyl amido phosphate ester.