Comparison of ultrasound-assisted, surfactant-assisted and conventional dispersive liquid-liquid microextraction coupled with flame atomic absorption spectrometry for the determination of copper

In this work, ultrasound assisted emulsification dispersive liquid-liquid microextraction (UAE-DLLME), surfactant assisted emulsification dispersive liquid-liquid microextraction (SAE-DLLME) and traditional DLLME coupled with flame atomic absorption spectrometry were applied in the determination of trace copper. The purpose of the developed work was to compare the analytical performance of the three kinds of DLLME techniques. After optimization, the analytical performance of UAE-DLLME was obviously better than that of SAE-DLLME and traditional DLLME. The LODs were respectively 0.6 mu g L-1, 0.8 mu g L-1 and 1.0 mg L-1, with enhancement factors of 30, 23 and 19. The relative standard deviations for seven replicate measurements of 50 mu g L-1 of copper were 3.4%, 3.1% and 3.7%, respectively. The recoveries for the spiked samples were in the acceptable range of 93.7-107.1%.