ASTM D3340 Test Method for Lithium and Sodium in Lubricating Greases by Flame Photometer
5. Apparatus
5.1 Flame Photometer, suitably equipped to determine lithium and sodium over a range from 0 to 15 mg/L lithium and from 0 to 5 mg/L sodium.
6. Reagents
6.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall 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.
6.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by Type II of Specification D1193.
6.3 Lithium Sulfate, Stock Solution - 1.188 g of lithium sulfate dried to constant weight at 180°C (356°F), is dissolved in water and made up to 1 L. This will contain 150 mg/L lithium.
6.4 Sodium Sulfate, Stock Solution - 0.1544 g of sodium sulfate, dried to constant weight at 105°C (221°F), is dissolved in water and made up to 1 L. This will contain 50 mg/L sodium.
6.5 Sulfuric Acid (rel. den. 1.84) - Concentrated sulfuric acid (H2SO4).
7. Sampling
7.1 A homogeneous sample shall be obtained to ensure quantitative analytical results.
