Evaluating Terephthalate as Probe Ion in the Analysis of Inorganic Anions by Capillary Electrophoresis with Indirect Photometric Detection

Abstract

A capillary electrophoresis method using terephthalate as probe ion in indirect photometric detection was investigated. The operating parameters including the pH and concentration of phosphate buffer, the applied potential, and the concentration of terephthalate were studied. Standard solutions containing known concentrations of chloride, sulfate, and fluoride were repeatedly analyzed. The calibration characteristics of analyzing these anions are calculated. The overall accuracy in terms of % recovery is between 95 and 102%. The detection limit ranges from 0.03 to 0.4 mM. The linearity covers more than 100 mM. The reproducibility in terms of % RSD is between 2 and 6%. The sensitivity of analysis ranges from 5.6 for chloride to 28.2 mAu∗min/mM for sulfate.

Keywords:

• Accuracy
• Anion
• Capillary electrophoresis
• Detection limit
• Indirect photometric detection
• Linearity
• Probe ion
• Reproducibility
• Sensitivity

ACKNOWLEDGMENT

The support of this work by The College of New Jersey through the SOSA grant is gratefully acknowledged.