Determination of Copper by Flame Atomic Absorption Spectrometry After Solid‐Phase Extraction

Abstract

A new solid‐phase extraction method was developed for trace analysis of copper. The method is based on the retention of copper as methylthymol blue complex on naphthalene–methyltrioctyl ammonium chloride adsorbent in a column. The adsorbed metal complex was eluted from the column with nitric acid, and its copper content was determined by flame atomic absorption spectrometry. The effect of different variables such as pH, reagent concentration, solution flow rate, and interfering ions on the recovery of the analyte was investigated. The calibration graph was linear in the range 5–200 ng mL⁻¹ of copper in the initial solution with r=0.9976. The 3S_b detection limit was 2 ng mL⁻¹, and the relative standard deviation for eight replicate measurements of 25 and 100 ng mL⁻¹ of copper was 4.2% and 1.7%, respectively. The method was applied to the determination of copper in river and sewage water samples.

Keywords:

• Copper
• methylthymol blue
• naphthalene–methyltrioctyl ammonium chloride adsorbent
• river water
• sewage water
• solid‐phase extraction

Acknowledgment

The financial support of this work by Shahid Chamran University Research Council is greatly acknowledged.