This method is used for the determination of low concentrations of phosphorus in lubricating oils. Metallic elements, such as iron, lead, magnesium and barium in amounts commonly encountered in lubricating oils do not interfere. This method may also be used for the analysis of additive concentrates containing phosphorus in the pentavalent state but is not recommended if the material contains more than 10 percent phosphorus.
IS 1448 Pt.101-1980 history
1981IS 1448 Pt.101-1980 Test methods for petroleum and its products [P: 101] Colorimetric determination of phosphorus in lubricating oils