ASTM D1091 test methods for phosphorus in lubricating oils and additives
5. Purity of Reagents
5.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
5.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by Type II or Type III of Specification D1193.
6. Sampling
6.1 Obtain samples in accordance with the instructions in Practices D4057 or D4177.
6.2 Take care that the test specimen is thoroughly representative of the material to be tested and that the portion of the sample is thoroughly representative of the test unit.
