Highly sensitive procedure for determination of Cu(II) by GF AAS using single-drop microextraction

A highly-sensitive method for Cu(II) determination employing single-drop microextraction (SDME) sample prior graphite-furnace atomic absorption spectrometry (GF AAS) is described. The chelating agent 1-(2-thiazolylazo)2-naphthol was used for copper complexation and favor mass transfer to the extractor solvent drop. An accessory for mechanized injection of the single drop was developed and a better performance of the extraction system was achieved in order to minimize intervention of the analyst in the drop formation. After extraction, the organic droplet was taken directly to GF AAS determinations. Limits of quantification and detection were estimated at 0.085 mu g L-1 and 0.025 mu g L-1, respectively, with an enrichment factor of 45.2. The procedure was successfully applied in the determination of copper in tap water and seawater. The combination of SDME and GF AAS proved to be a suitable strategy to achieve an analytical method with high detectability for copper. Additionally, the low consumption of samples and reagents, and the minimal waste generation make the procedure environmentally friendly.