Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D6173-97 – Standard Test Method Technical Guide
ASTM D6173-97 (Reapproved 2014) provides a standard test method for the determination of various anionic surfactant actives using potentiometric titration. This method is designed as an environmentally friendly alternative to traditional two-phase titrations that involve hazardous chloroform. It focuses on common anionic surfactants used in synthetic detergents and household cleaners.
📐 Standard Scope and Applicable Surfactants
The method is specifically intended for the analysis of active matter in alcohol ether sulfate, alpha olefin sulfonate, alkylbenzene sulfonic acid, alcohol sulfate, and blends of sodium alkylbenzene sulfonate with sodium xylene sulfonate in ratios of 5:1, 16:1, and 22:1. It has not been tested for formulated detergent products, ensuring focus on raw materials.
| 🟦 Surfactant Type | 📏 Application in Detergents |
|---|---|
| Alcohol Ether Sulfate | Common anionic active in liquid detergents |
| Alpha Olefin Sulfonate | Used in high-efficiency cleaners |
| Alkylbenzene Sulfonic Acid | Key ingredient in synthetic detergents |
| Alcohol Sulfate | Found in powdered detergents |
| Sodium Alkylbenzene Sulfonate/Sodium Xylene Sulfonate Blends | Ratios of 5:1, 16:1, 22:1 for specific formulations |
⚙️ Test Procedure and Methodology
The sample is dissolved in water, and the pH is adjusted according to the type of anionic surfactant. The titration is carried out potentiometrically using a standard Hyamine solution. A surfactant electrode tracks the potential, and the endpoint is marked by a sharp inflection due to excess