ASTM D2110 – pH of water Extractions of Halogenated Organic Solvents and Their Admixtures
Halogenated organic solvents are often prepared with either mildly acidic or mildly basic pH stabilizers to lessen oxidation and degradation. The stabilizers are usually water soluble, and their levels may often be determined by extracting them into water and measuring the pH of the resulting aqueous solution. In new or reclaimed solvents, a pH variance outside the intended range may indicate a quality control problem. In used solvents, a pH variance may indicate a contamination or breakdown of the solvent. This test determines the pH of water extractions of halogenated organic solvents.
In a separatory funnel, distilled water is added to the sample. The mixture is shaken, the layers are allowed to separate and the water layer is removed. The pH of the water layer may be determined either by adding a color indicator and matching the resulting color to a standard chart (Procedure A) or by direct measurement with a pH meter using a glass electrode (Procedure B). For Procedure A, the pH is reported to the nearest 0.25 pH unit. For Procedure B, the pH is reported to the nearest 0.1 pH unit. Please specify Procedure A or Procedure B.