Determination of Copper in Water and Walnuts by Solid Phase Extraction and Slotted Quartz Tube Flame Atomic Absorption Spectrometry

ABSTRACT

Cu(II) was separated and preconcentrated using solid phase extraction and a slotted quartz tube (SQT) and determined in drinking water and walnuts by flame atomic absorption spectrometry. The procedure is based on the sorption of copper(II) on a column filled with a resin followed by elution with 5 mL of 3 mol L⁻¹ nitric acid in the first preconcentration step. To increase the sensitivity of system, the preconcentration parameters for copper(II) were optimized. The SQT was used as the second preconcentration step to further improve the sensitivity. The enrichment factor and detection limits were 640 and 0.23 µg L⁻¹, respectively. Another advantage of this method is the presence of a wide pH range for copper(II) sorption with high effectiveness in acidic media. The accuracy of method was confirmed by the analysis of a spinach leaves certified reference material (NIST 1570a).

KEYWORDS:

• Copper
• flame atomic absorption spectrometry
• slotted quartz tube
• solid phase extraction
• two-step preconcentration

Acknowledgment

This study was performed in Mehmet Akif Ersoy University at Burdur.