ANALYTICAL LETTERS, vol.48, no.11, pp.1738-1750, 2015 (SCI-Expanded)
A new, simple, and rapid ionic liquid based dispersive liquid-liquid microextraction method is reported for the determination of copper with flame atomic absorption spectrometry. The ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was used to extract a copper(II)- curcumin complex. The optimum extraction efficiency of copper was obtained after optimization of the ionic liquid volume, pH, centrifugation speed and time, ultrasonic bath time and temperature, and mass of curcumin. The effects of various ions on the recovery of copper(II) were also investigated. The preconcentration factor was 135. In the optimum experimental conditions, the limit of detection and the relative standard deviation were 0.19 microgram per liter and 4.1 percent, respectively. The method was validated by the analysis of certified reference materials and applied to food and water.