Solid phase extraction of trace cobalt (II) in industrial wastewaters by modified nanotube carbon carboxyl and its determination with flame atomic spectroscopy

Applying a simple and selective sample preparation procedure prior to instrumental analysis is the most important and crucial step in an analytical process. Up to now, various sample preparation techniques based on solid phase extraction (SPE) systems have been developed to isolate various types of analytes from different matrices. In the method presented for preconcentration and measurement of trace amounts of cobalt (II) ions in aqueous samples, carbon nanotubes functionalized with carboxyl were used for improving the extraction and preconcentration action. Measurement of Co2+ ion concentration in aqueous solutions was performed by flame atomic absorption spectroscopy. The parameters including the extraction including pH, amount and type of desorption solvent, extraction time, the effect of other ions, etc. were optimized. The concentration factor, level of detection (LOD) of the method, and relative standard deviation (RSD %) were obtained as 20.83, 6 µg.L-1, and 1.16%, respectively.