Measurement of Chelating Agent Levels in Media with High Concentrations of Interfering Metal Ions

Abstract

An ion-exchange method for the measurement of levels of chelating agents in media with high levels of metal ions has been developed. The test solution is passed through a specially prepared ion-exchange column, which both removes metal ion interferences, and places the chelating agent in the copper form. The copper levels in the column effluent are then measured by flame atomic absorption methods, the copper levels corresponding in a 1:1 ratio to the levels of chelating agent in the sample. The detection limit for this method is on the order of 1 ppm copper equivalent chelating capacity, and is applicable in situations where the interfering metal ions are at concentrations in the range of 10⁻² M. The method is reproducible in the pH ranges of 4 to 9 Precision and

Key Words:

• Chelating Agents
• Atomic Absorption
• Chromatography