Dispersive liquid-liquid microextraction of Fe(II) and Cu(II) with diethyldithiocarbamate and their simultaneous spectrophotometric determination using mean centering of ratio spectra

A new dispersive liquid-liquid microextraction (DLLME) method for preconcentration of trace quantities of Fe(II) and Cu(II) followed by their spectrophotometric determination has been developed. For the extraction, an appropriate mixture of ethanol (the disperser solvent) and carbon tetrachloride (the extraction solvent) was injected rapidly into the water sample containing Fe(II) and Cu(II) after formation of complexes with diethyldithiocarbamate. Mean centering (MC) of ratio spectra has been used for simultaneous determination of Fe(II) and Cu(II). Linear range of the method is 1.0-100 ng/mL for Fe(II) and 0.3-100 ng/mL for Cu(II), the detection limit is 0.53 ng/mL and 0.14 ng/mL Cu(II), resp. The interference effect of some anions and cations is reported. The method was applied to the determination of Fe(II) and Cu(II) in well water samples.