The present work reports a procedure based on ligandless-ultrasound-assisted emulsification-microextraction of trace amounts of cobalt and manganese ions in water samples prior to flame atomic absorption spectrometry determination (FAAS). Different factors influencing the extraction efficiency of cobalt and manganese ions, such as type and volume of the extraction solvent, pH, extraction time, extraction temperature, and ionic strength were studied and optimized. Cobalt and manganese ions were extracted in an acoustically emulsified media by 20.0 μL carbon tetrachloride. The limits of detection were 0.8 and 0.5 ng mL-1 for Co(II) and Mn(II), respectively (3Sb/m). Eight replicate determinations of a mixture of 100.0 ng mL-1 cobalt and 50.0 ng mL-1 manganese gave a mean absorbance of 0.055 and 0.061 with relative standard deviations of 3.2 and 2.9%, respectively. The proposed procedure was successfully applied to determination of cobalt and manganese in water samples.
ultrasound-assisted extraction; emulsification microextraction; ligandless; preconcentration; cobalt; manganese
