Knowledge of the phosphorus content, and thus the phosphorus-containing additives, in a lubricating oil or additive can be used to predict performance characteristics. This test method is suitable for most applications requiring the determination of phosphorus.

1.1 These test methods cover the determination of phosphorus in unused lubricating oils and lubricating oil additives and their concentrates. The test methods are not restricted with respect to the type of phosphorus compounds that may be presentfor example, trivalent or pentavalent phosphorus compounds, phosphines, phosphates, phosphonates, phosphorus sulfides, and so forthsince all are quantitatively converted to an aqueous solution of orthophosphate ion by oxidation of the sample during the course of analysis.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

7.1 This test method covers a procedure for removal of organic material and subsequent conversion of phosphorus to phosphate ion in samples of unused lubricating oils, lubricating oil additives, and their concentrates.

12.1 This test method covers determination of total phosphorus in concentrations of less than two mass % (see Note 6), calculated on the basis of the original test specimen, in samples treated by the acid-oxidation procedure described in Sections 7-11.

Note 6—For phosphorus concentrations greater than or equal to two mass %, see Sections 19-25.

19.1 This test method covers the determination of total phosphorus in concentrations of 2 mass % or more, (see Note 10), calculated on the basis of the original sample, in samples treated by the acid-oxidation procedure described in Sections 7-11.

Note 10—For phosphorus concentrations less than 2 mass %, see Sections 12-18.