This standard specifies the method for determination of the phosphorus content in additive and lubrication oil containing additive.
This standard is applicable to additive and lubrication oil containing additive.
2 Summary of Method
At high temperature, use ZnO as trapping agent and produce P2O5 with P in specimen and keep it in ZnO. Then dissolve ZnO with nitric acid and turn P2O5 into phosphate radical. In a certain range of acidity, phosphate radical and ammonium vanadate-ammonium molybdate produce a stable yellow complex, and then conduct colorimetric analysis at 460nm wavelength.
